diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/DMA-API.txt | 3 | ||||
| -rw-r--r-- | Documentation/DocBook/Makefile | 2 | ||||
| -rw-r--r-- | Documentation/DocBook/s390-drivers.tmpl | 149 | ||||
| -rw-r--r-- | Documentation/MSI-HOWTO.txt | 69 | ||||
| -rw-r--r-- | Documentation/filesystems/ntfs.txt | 4 | ||||
| -rw-r--r-- | Documentation/ja_JP/HOWTO | 84 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 19 | ||||
| -rw-r--r-- | Documentation/kobject.txt | 22 | ||||
| -rw-r--r-- | Documentation/s390/00-INDEX | 26 | ||||
| -rw-r--r-- | Documentation/s390/CommonIO | 51 | ||||
| -rw-r--r-- | Documentation/s390/cds.txt | 8 | ||||
| -rw-r--r-- | Documentation/usb/authorization.txt | 92 | ||||
| -rw-r--r-- | Documentation/usb/power-management.txt | 517 | ||||
| -rw-r--r-- | Documentation/usb/usb-serial.txt | 11 | ||||
| -rw-r--r-- | Documentation/usb/usbmon.txt | 9 |
15 files changed, 913 insertions, 153 deletions
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index cc7a8c3..b939ebb 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -68,6 +68,9 @@ size and dma_handle must all be the same as those passed into the consistent allocate. cpu_addr must be the virtual address returned by the consistent allocate. +Note that unlike their sibling allocation calls, these routines +may only be called with IRQs enabled. + Part Ib - Using small dma-coherent buffers ------------------------------------------ diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile index 08687e4..1a7f530 100644 --- a/Documentation/DocBook/Makefile +++ b/Documentation/DocBook/Makefile @@ -11,7 +11,7 @@ DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \ procfs-guide.xml writing_usb_driver.xml \ kernel-api.xml filesystems.xml lsm.xml usb.xml \ gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \ - genericirq.xml + genericirq.xml s390-drivers.xml ### # The build process is as follows (targets): diff --git a/Documentation/DocBook/s390-drivers.tmpl b/Documentation/DocBook/s390-drivers.tmpl new file mode 100644 index 0000000..254e769 --- /dev/null +++ b/Documentation/DocBook/s390-drivers.tmpl @@ -0,0 +1,149 @@ +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" + "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []> + +<book id="s390drivers"> + <bookinfo> + <title>Writing s390 channel device drivers</title> + + <authorgroup> + <author> + <firstname>Cornelia</firstname> + <surname>Huck</surname> + <affiliation> + <address> + <email>cornelia.huck@de.ibm.com</email> + </address> + </affiliation> + </author> + </authorgroup> + + <copyright> + <year>2007</year> + <holder>IBM Corp.</holder> + </copyright> + + <legalnotice> + <para> + This documentation is free software; you can redistribute + it and/or modify it under the terms of the GNU General Public + License as published by the Free Software Foundation; either + version 2 of the License, or (at your option) any later + version. + </para> + + <para> + This program is distributed in the hope that it will be + useful, but WITHOUT ANY WARRANTY; without even the implied + warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + See the GNU General Public License for more details. + </para> + + <para> + You should have received a copy of the GNU General Public + License along with this program; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, + MA 02111-1307 USA + </para> + + <para> + For more details see the file COPYING in the source + distribution of Linux. + </para> + </legalnotice> + </bookinfo> + +<toc></toc> + + <chapter id="intro"> + <title>Introduction</title> + <para> + This document describes the interfaces available for device drivers that + drive s390 based channel attached devices. This includes interfaces for + interaction with the hardware and interfaces for interacting with the + common driver core. Those interfaces are provided by the s390 common I/O + layer. + </para> + <para> + The document assumes a familarity with the technical terms associated + with the s390 channel I/O architecture. For a description of this + architecture, please refer to the "z/Architecture: Principles of + Operation", IBM publication no. SA22-7832. + </para> + <para> + While most I/O devices on a s390 system are typically driven through the + channel I/O mechanism described here, there are various other methods + (like the diag interface). These are out of the scope of this document. + </para> + <para> + Some additional information can also be found in the kernel source + under Documentation/s390/driver-model.txt. + </para> + </chapter> + <chapter id="ccw"> + <title>The ccw bus</title> + <para> + The ccw bus typically contains the majority of devices available to + a s390 system. Named after the channel command word (ccw), the basic + command structure used to address its devices, the ccw bus contains + so-called channel attached devices. They are addressed via subchannels, + visible on the css bus. A device driver, however, will never interact + with the subchannel directly, but only via the device on the ccw bus, + the ccw device. + </para> + <sect1 id="channelIO"> + <title>I/O functions for channel-attached devices</title> + <para> + Some hardware structures have been translated into C structures for use + by the common I/O layer and device drivers. For more information on + the hardware structures represented here, please consult the Principles + of Operation. + </para> +!Iinclude/asm-s390/cio.h + </sect1> + <sect1 id="ccwdev"> + <title>ccw devices</title> + <para> + Devices that want to initiate channel I/O need to attach to the ccw bus. + Interaction with the driver core is done via the common I/O layer, which + provides the abstractions of ccw devices and ccw device drivers. + </para> + <para> + The functions that initiate or terminate channel I/O all act upon a + ccw device structure. Device drivers must not bypass those functions + or strange side effects may happen. + </para> +!Iinclude/asm-s390/ccwdev.h +!Edrivers/s390/cio/device.c +!Edrivers/s390/cio/device_ops.c + </sect1> + <sect1 id="cmf"> + <title>The channel-measurement facility</title> + <para> + The channel-measurement facility provides a means to collect + measurement data which is made available by the channel subsystem + for each channel attached device. + </para> +!Iinclude/asm-s390/cmb.h +!Edrivers/s390/cio/cmf.c + </sect1> + </chapter> + + <chapter id="ccwgroup"> + <title>The ccwgroup bus</title> + <para> + The ccwgroup bus only contains artificial devices, created by the user. + Many networking devices (e.g. qeth) are in fact composed of several + ccw devices (like read, write and data channel for qeth). The + ccwgroup bus provides a mechanism to create a meta-device which + contains those ccw devices as slave devices and can be associated + with the netdevice. + </para> + <sect1 id="ccwgroupdevices"> + <title>ccw group devices</title> +!Iinclude/asm-s390/ccwgroup.h +!Edrivers/s390/cio/ccwgroup.c + </sect1> + </chapter> + +</book> diff --git a/Documentation/MSI-HOWTO.txt b/Documentation/MSI-HOWTO.txt index 0d82407..a51f693 100644 --- a/Documentation/MSI-HOWTO.txt +++ b/Documentation/MSI-HOWTO.txt @@ -241,68 +241,7 @@ address space of the MSI-X table/MSI-X PBA. Otherwise, the PCI subsystem will fail enabling MSI-X on its hardware device when it calls the function pci_enable_msix(). -5.3.2 Handling MSI-X allocation - -Determining the number of MSI-X vectors allocated to a function is -dependent on the number of MSI capable devices and MSI-X capable -devices populated in the system. The policy of allocating MSI-X -vectors to a function is defined as the following: - -#of MSI-X vectors allocated to a function = (x - y)/z where - -x = The number of available PCI vector resources by the time - the device driver calls pci_enable_msix(). The PCI vector - resources is the sum of the number of unassigned vectors - (new) and the number of released vectors when any MSI/MSI-X - device driver switches its hardware device back to a legacy - mode or is hot-removed. The number of unassigned vectors - may exclude some vectors reserved, as defined in parameter - NR_HP_RESERVED_VECTORS, for the case where the system is - capable of supporting hot-add/hot-remove operations. Users - may change the value defined in NR_HR_RESERVED_VECTORS to - meet their specific needs. - -y = The number of MSI capable devices populated in the system. - This policy ensures that each MSI capable device has its - vector reserved to avoid the case where some MSI-X capable - drivers may attempt to claim all available vector resources. - -z = The number of MSI-X capable devices populated in the system. - This policy ensures that maximum (x - y) is distributed - evenly among MSI-X capable devices. - -Note that the PCI subsystem scans y and z during a bus enumeration. -When the PCI subsystem completes configuring MSI/MSI-X capability -structure of a device as requested by its device driver, y/z is -decremented accordingly. - -5.3.3 Handling MSI-X shortages - -For the case where fewer MSI-X vectors are allocated to a function -than requested, the function pci_enable_msix() will return the -maximum number of MSI-X vectors available to the caller. A device -driver may re-send its request with fewer or equal vectors indicated -in the return. For example, if a device driver requests 5 vectors, but -the number of available vectors is 3 vectors, a value of 3 will be -returned as a result of pci_enable_msix() call. A function could be -designed for its driver to use only 3 MSI-X table entries as -different combinations as ABC--, A-B-C, A--CB, etc. Note that this -patch does not support multiple entries with the same vector. Such -attempt by a device driver to use 5 MSI-X table entries with 3 vectors -as ABBCC, AABCC, BCCBA, etc will result as a failure by the function -pci_enable_msix(). Below are the reasons why supporting multiple -entries with the same vector is an undesirable solution. - - - The PCI subsystem cannot determine the entry that - generated the message to mask/unmask MSI while handling - software driver ISR. Attempting to walk through all MSI-X - table entries (2048 max) to mask/unmask any match vector - is an undesirable solution. - - - Walking through all MSI-X table entries (2048 max) to handle - SMP affinity of any match vector is an undesirable solution. - -5.3.4 API pci_enable_msix +5.3.2 API pci_enable_msix int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec) @@ -339,7 +278,7 @@ a failure. This failure may be a result of duplicate entries specified in second argument, or a result of no available vector, or a result of failing to initialize MSI-X table entries. -5.3.5 API pci_disable_msix +5.3.3 API pci_disable_msix void pci_disable_msix(struct pci_dev *dev) @@ -349,7 +288,7 @@ always call free_irq() on all MSI-X vectors it has done request_irq() on before calling this API. Failure to do so results in a BUG_ON() and a device will be left with MSI-X enabled and leaks its vectors. -5.3.6 MSI-X mode vs. legacy mode diagram +5.3.4 MSI-X mode vs. legacy mode diagram The below diagram shows the events which switch the interrupt mode on the MSI-X capable device function between MSI-X mode and @@ -407,7 +346,7 @@ between MSI mod MSI-X mode during a run-time. MSI/MSI-X support requires support from both system hardware and individual hardware device functions. -5.5.1 System hardware support +5.5.1 Required x86 hardware support Since the target of MSI address is the local APIC CPU, enabling MSI/MSI-X support in the Linux kernel is dependent on whether existing diff --git a/Documentation/filesystems/ntfs.txt b/Documentation/filesystems/ntfs.txt index 8ee10ec..e79ee2d 100644 --- a/Documentation/filesystems/ntfs.txt +++ b/Documentation/filesystems/ntfs.txt @@ -407,7 +407,7 @@ raiddev /dev/md0 device /dev/hda5 raid-disk 0 device /dev/hdb1 - raid-disl 1 + raid-disk 1 For linear raid, just change the raid-level above to "raid-level linear", for mirrors, change it to "raid-level 1", and for stripe sets with parity, change @@ -457,6 +457,8 @@ ChangeLog Note, a technical ChangeLog aimed at kernel hackers is in fs/ntfs/ChangeLog. +2.1.29: + - Fix a deadlock when mounting read-write. 2.1.28: - Fix a deadlock. 2.1.27: diff --git a/Documentation/ja_JP/HOWTO b/Documentation/ja_JP/HOWTO index 9f08dab..d9d832c 100644 --- a/Documentation/ja_JP/HOWTO +++ b/Documentation/ja_JP/HOWTO @@ -1,4 +1,4 @@ -NOTE: +NOTE: This is a version of Documentation/HOWTO translated into Japanese. This document is maintained by Tsugikazu Shibata <tshibata@ab.jp.nec.com> and the JF Project team <www.linux.or.jp/JF>. @@ -11,14 +11,14 @@ for non English (read: Japanese) speakers and is not intended as a fork. So if you have any comments or updates for this file, please try to update the original English file first. -Last Updated: 2007/07/18 +Last Updated: 2007/09/23 ================================== これは、 -linux-2.6.22/Documentation/HOWTO +linux-2.6.23/Documentation/HOWTO の和訳です。 翻訳団体： JF プロジェクト < http://www.linux.or.jp/JF/ > -翻訳日： 2007/07/16 +翻訳日： 2007/09/19 翻訳者： Tsugikazu Shibata <tshibata at ab dot jp dot nec dot com> 校正者： 松倉さん <nbh--mats at nifty dot com> 小林 雅典さん (Masanori Kobayasi) <zap03216 at nifty dot ne dot jp> @@ -27,6 +27,7 @@ linux-2.6.22/Documentation/HOWTO 野口さん (Kenji Noguchi) <tokyo246 at gmail dot com> 河内さん (Takayoshi Kochi) <t-kochi at bq dot jp dot nec dot com> 岩本さん (iwamoto) <iwamoto.kn at ncos dot nec dot co dot jp> + 内田さん (Satoshi Uchida) <s-uchida at ap dot jp dot nec dot com> ================================== Linux カーネル開発のやり方 @@ -40,7 +41,7 @@ Linux カーネル開発コミュニティと共に活動するやり方を学 手助けになります。 もし、このドキュメントのどこかが古くなっていた場合には、このドキュメン -トの最後にリストしたメンテナーにパッチを送ってください。 +トの最後にリストしたメンテナにパッチを送ってください。 はじめに --------- @@ -59,7 +60,7 @@ Linux カーネル開発コミュニティと共に活動するやり方を学 ネル開発者には必要です。アーキテクチャ向けの低レベル部分の開発をするの でなければ、(どんなアーキテクチャでも)アセンブリ(訳注: 言語)は必要あり ません。以下の本は、C 言語の十分な知識や何年もの経験に取って代わるもの -ではありませんが、少なくともリファレンスとしてはいい本です。 +ではありませんが、少なくともリファレンスとしては良い本です。 - "The C Programming Language" by Kernighan and Ritchie [Prentice Hall] -『プログラミング言語Ｃ第2版』(B.W. カーニハン/D.M. リッチー著 石田晴久訳) [共立出版] - "Practical C Programming" by Steve Oualline [O'Reilly] @@ -76,7 +77,7 @@ Linux カーネル開発コミュニティと共に活動するやり方を学 ときどき、カーネルがツールチェインや C 言語拡張に置いている前提がどう なっているのかわかりにくいことがあり、また、残念なことに決定的なリファ レンスは存在しません。情報を得るには、gcc の info ページ( info gcc )を -みてください。 +見てください。 あなたは既存の開発コミュニティと一緒に作業する方法を学ぼうとしているこ とに留意してください。そのコミュニティは、コーディング、スタイル、 @@ -92,7 +93,7 @@ Linux カーネル開発コミュニティと共に活動するやり方を学 Linux カーネルのソースコードは GPL ライセンスの下でリリースされていま す。ライセンスの詳細については、ソースツリーのメインディレクトリに存在 -する、COPYING のファイルをみてください。もしライセンスについてさらに質 +する、COPYING のファイルを見てください。もしライセンスについてさらに質 問があれば、Linux Kernel メーリングリストに質問するのではなく、どうぞ 法律家に相談してください。メーリングリストの人達は法律家ではなく、法的 問題については彼らの声明はあてにするべきではありません。 @@ -109,7 +110,8 @@ Linux カーネルソースツリーは幅広い範囲のドキュメントを 新しいドキュメントファイルも追加することを勧めます。 カーネルの変更が、カーネルがユーザ空間に公開しているインターフェイスの 変更を引き起こす場合、その変更を説明するマニュアルページのパッチや情報 -をマニュアルページのメンテナ mtk-manpages@gmx.net に送ることを勧めます。 +をマニュアルページのメンテナ mtk-manpages@gmx.net に送ることを勧めま +す。 以下はカーネルソースツリーに含まれている読んでおくべきファイルの一覧で す- @@ -117,7 +119,7 @@ Linux カーネルソースツリーは幅広い範囲のドキュメントを README このファイルは Linuxカーネルの簡単な背景とカーネルを設定(訳注 configure )し、生成(訳注 build )するために必要なことは何かが書かれ - ています。カーネルに関して初めての人はここからスタートするとよいで + ています。カーネルに関して初めての人はここからスタートすると良いで しょう。 Documentation/Changes @@ -128,7 +130,7 @@ Linux カーネルソースツリーは幅広い範囲のドキュメントを Documentation/CodingStyle これは Linux カーネルのコーディングスタイルと背景にある理由を記述 しています。全ての新しいコードはこのドキュメントにあるガイドライン - に従っていることを期待されています。大部分のメンテナーはこれらのルー + に従っていることを期待されています。大部分のメンテナはこれらのルー ルに従っているものだけを受け付け、多くの人は正しいスタイルのコード だけをレビューします。 @@ -168,16 +170,16 @@ Linux カーネルソースツリーは幅広い範囲のドキュメントを 支援してください。 Documentation/ManagementStyle - このドキュメントは Linux カーネルのメンテナー達がどう行動するか、 + このドキュメントは Linux カーネルのメンテナ達がどう行動するか、 彼らの手法の背景にある共有されている精神について記述しています。こ れはカーネル開発の初心者なら（もしくは、単に興味があるだけの人でも） - 重要です。なぜならこのドキュメントは、カーネルメンテナー達の独特な + 重要です。なぜならこのドキュメントは、カーネルメンテナ達の独特な 行動についての多くの誤解や混乱を解消するからです。 Documentation/stable_kernel_rules.txt このファイルはどのように stable カーネルのリリースが行われるかのルー ルが記述されています。そしてこれらのリリースの中のどこかで変更を取 - り入れてもらいたい場合に何をすればいいかが示されています。 + り入れてもらいたい場合に何をすれば良いかが示されています。 Documentation/kernel-docs.txt カーネル開発に付随する外部ドキュメントのリストです。もしあなたが @@ -218,9 +220,9 @@ web サイトには、コードの構成、サブシステム、現在存在す ここには、また、カーネルのコンパイルのやり方やパッチの当て方などの間接 的な基本情報も記述されています。 -あなたがどこからスタートしてよいかわからないが、Linux カーネル開発コミュ +あなたがどこからスタートして良いかわからないが、Linux カーネル開発コミュ ニティに参加して何かすることをさがしている場合には、Linux kernel -Janitor's プロジェクトにいけばよいでしょう - +Janitor's プロジェクトにいけば良いでしょう - http://janitor.kernelnewbies.org/ ここはそのようなスタートをするのにうってつけの場所です。ここには、 Linux カーネルソースツリーの中に含まれる、きれいにし、修正しなければな @@ -243,7 +245,7 @@ Linux カーネルソースツリーの中に含まれる、きれいにし、 自己参照方式で、索引がついた web 形式で、ソースコードを参照することが できます。この最新の素晴しいカーネルコードのリポジトリは以下で見つかり ます- - http://sosdg.org/~coywolf/lxr/ + http://sosdg.org/~qiyong/lxr/ 開発プロセス ----------------------- @@ -265,9 +267,9 @@ Linux カーネルの開発プロセスは現在幾つかの異なるメイン 以下のとおり- - 新しいカーネルがリリースされた直後に、2週間の特別期間が設けられ、 - この期間中に、メンテナー達は Linus に大きな差分を送ることができま - す。このような差分は通常 -mm カーネルに数週間含まれてきたパッチで - す。 大きな変更は git(カーネルのソース管理ツール、詳細は + この期間中に、メンテナ達は Linus に大きな差分を送ることができます。 + このような差分は通常 -mm カーネルに数週間含まれてきたパッチです。 + 大きな変更は git(カーネルのソース管理ツール、詳細は http://git.or.cz/ 参照) を使って送るのが好ましいやり方ですが、パッ チファイルの形式のまま送るのでも十分です。 @@ -285,6 +287,10 @@ Linux カーネルの開発プロセスは現在幾つかの異なるメイン に安定した状態にあると判断したときにリリースされます。目標は毎週新 しい -rc カーネルをリリースすることです。 + - 以下の URL で各 -rc リリースに存在する既知の後戻り問題のリスト + が追跡されます- + http://kernelnewbies.org/known_regressions + - このプロセスはカーネルが 「準備ができた」と考えられるまで継続しま す。このプロセスはだいたい 6週間継続します。 @@ -331,8 +337,8 @@ Andrew は個別のサブシステムカーネルツリーとパッチを全て linux-kernel メーリングリストで収集された多数のパッチと同時に一つにま とめます。 このツリーは新機能とパッチが検証される場となります。ある期間の間パッチ -が -mm に入って価値を証明されたら、Andrew やサブシステムメンテナが、メ -インラインへ入れるように Linus にプッシュします。 +が -mm に入って価値を証明されたら、Andrew やサブシステムメンテナが、 +メインラインへ入れるように Linus にプッシュします。 メインカーネルツリーに含めるために Linus に送る前に、すべての新しいパッ チが -mm ツリーでテストされることが強く推奨されます。 @@ -460,7 +466,7 @@ MAINTAINERS ファイルにリストがありますので参照してくださ せん- 彼らはあなたのパッチの行毎にコメントを入れたいので、そのためにはそうす るしかありません。あなたのメールプログラムが空白やタブを圧縮しないよう -に確認した方がいいです。最初の良いテストとしては、自分にメールを送って +に確認した方が良いです。最初の良いテストとしては、自分にメールを送って みて、そのパッチを自分で当ててみることです。もしそれがうまく行かないな ら、あなたのメールプログラムを直してもらうか、正しく動くように変えるべ きです。 @@ -507,14 +513,14 @@ MAINTAINERS ファイルにリストがありますので参照してくださ とも普通のことです。これはあなたのパッチが受け入れられないということで は *ありません*、そしてあなた自身に反対することを意味するのでも *ありま せん*。単に自分のパッチに対して指摘された問題を全て修正して再送すれば -いいのです。 +良いのです。 カーネルコミュニティと企業組織のちがい ----------------------------------------------------------------- カーネルコミュニティは大部分の伝統的な会社の開発環境とは異ったやり方で -動いています。以下は問題を避けるためにできるとよいことののリストです- +動いています。以下は問題を避けるためにできると良いことのリストです- あなたの提案する変更について言うときのうまい言い方： @@ -525,7 +531,7 @@ MAINTAINERS ファイルにリストがありますので参照してくださ - "以下は一連の小さなパッチ群ですが..." - "これは典型的なマシンでの性能を向上させます.." - やめた方がいい悪い言い方： + やめた方が良い悪い言い方： - このやり方で AIX/ptx/Solaris ではできたので、できるはずだ - 私はこれを20年もの間やってきた、だから @@ -575,10 +581,10 @@ Linux カーネルコミュニティは、一度に大量のコードの塊を 1) 小さいパッチはあなたのパッチが適用される見込みを大きくします、カー ネルの人達はパッチが正しいかどうかを確認する時間や労力をかけないか - らです。5行のパッチはメンテナがたった1秒見るだけで適用できます。し - かし、500行のパッチは、正しいことをレビューするのに数時間かかるかも - しれません(時間はパッチのサイズなどにより指数関数に比例してかかりま - す) + らです。5行のパッチはメンテナがたった1秒見るだけで適用できます。 + しかし、500行のパッチは、正しいことをレビューするのに数時間かかるか + もしれません(時間はパッチのサイズなどにより指数関数に比例してかかり + ます) 小さいパッチは何かあったときにデバッグもとても簡単になります。パッ チを1個1個取り除くのは、とても大きなパッチを当てた後に(かつ、何かお @@ -587,23 +593,23 @@ Linux カーネルコミュニティは、一度に大量のコードの塊を 2) 小さいパッチを送るだけでなく、送るまえに、書き直して、シンプルにす る(もしくは、単に順番を変えるだけでも)ことも、とても重要です。 -以下はカーネル開発者の Al Viro のたとえ話しです： +以下はカーネル開発者の Al Viro のたとえ話です： "生徒の数学の宿題を採点する先生のことを考えてみてください、先 - 生は生徒が解に到達するまでの試行錯誤をみたいとは思わないでしょ - う。先生は簡潔な最高の解をみたいのです。良い生徒はこれを知って + 生は生徒が解に到達するまでの試行錯誤を見たいとは思わないでしょ + う。先生は簡潔な最高の解を見たいのです。良い生徒はこれを知って おり、そして最終解の前の中間作業を提出することは決してないので す" - カーネル開発でもこれは同じです。メンテナー達とレビューア達は、 - 問題を解決する解の背後になる思考プロセスをみたいとは思いません。 - 彼らは単純であざやかな解決方法をみたいのです。 + カーネル開発でもこれは同じです。メンテナ達とレビューア達は、 + 問題を解決する解の背後になる思考プロセスを見たいとは思いません。 + 彼らは単純であざやかな解決方法を見たいのです。 あざやかな解を説明するのと、コミュニティと共に仕事をし、未解決の仕事を 議論することのバランスをキープするのは難しいかもしれません。 ですから、開発プロセスの早期段階で改善のためのフィードバックをもらうよ -うにするのもいいですが、変更点を小さい部分に分割して全体ではまだ完成し -ていない仕事を(部分的に)取り込んでもらえるようにすることもいいことです。 +うにするのも良いですが、変更点を小さい部分に分割して全体ではまだ完成し +ていない仕事を(部分的に)取り込んでもらえるようにすることも良いことです。 また、でき上がっていないものや、"将来直す" ようなパッチを、本流に含め てもらうように送っても、それは受け付けられないことを理解してください。 @@ -629,7 +635,7 @@ Linux カーネルコミュニティは、一度に大量のコードの塊を - テスト結果 これについて全てがどのようにあるべきかについての詳細は、以下のドキュメ -ントの ChangeLog セクションをみてください- +ントの ChangeLog セクションを見てください- "The Perfect Patch" http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 4881080..c323778 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -68,6 +68,7 @@ parameter is applicable: PARIDE The ParIDE (parallel port IDE) subsystem is enabled. PARISC The PA-RISC architecture is enabled. PCI PCI bus support is enabled. + PCIE PCI Express support is enabled. PCMCIA The PCMCIA subsystem is enabled. PNP Plug & Play support is enabled. PPC PowerPC architecture is enabled. @@ -1013,6 +1014,10 @@ and is between 256 and 4096 characters. It is defined in the file meye.*= [HW] Set MotionEye Camera parameters See Documentation/video4linux/meye.txt. + mfgpt_irq= [IA-32] Specify the IRQ to use for the + Multi-Function General Purpose Timers on AMD Geode + platforms. + mga= [HW,DRM] mousedev.tap_time= @@ -1160,6 +1165,9 @@ and is between 256 and 4096 characters. It is defined in the file nomce [X86-32] Machine Check Exception + nomfgpt [X86-32] Disable Multi-Function General Purpose + Timer usage (for AMD Geode machines). + noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops noreplace-smp [X86-32,SMP] Don't replace SMP instructions @@ -1270,6 +1278,11 @@ and is between 256 and 4096 characters. It is defined in the file Mechanism 1. conf2 [X86-32] Force use of PCI Configuration Mechanism 2. + noaer [PCIE] If the PCIEAER kernel config parameter is + enabled, this kernel boot option can be used to + disable the use of PCIE advanced error reporting. + nodomains [PCI] Disable support for multiple PCI + root domains (aka PCI segments, in ACPI-speak). nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI Configuration nomsi [MSI] If the PCI_MSI kernel config parameter is @@ -1314,6 +1327,8 @@ and is between 256 and 4096 characters. It is defined in the file IRQ routing is enabled. noacpi [X86-32] Do not use ACPI for IRQ routing or for PCI scanning. + use_crs [X86-32] Use _CRS for PCI resource + allocation. routeirq Do IRQ routing for all PCI devices. This is normally done in pci_enable_device(), so this option is a temporary workaround @@ -1430,6 +1445,10 @@ and is between 256 and 4096 characters. It is defined in the file pt. [PARIDE] See Documentation/paride.txt. + pty.legacy_count= + [KNL] Number of legacy pty's. Overwrites compiled-in + default number. + quiet [KNL] Disable most log messages r128= [HW,DRM] diff --git a/Documentation/kobject.txt b/Documentation/kobject.txt index 8ee49ee..ca86a88 100644 --- a/Documentation/kobject.txt +++ b/Documentation/kobject.txt @@ -54,7 +54,6 @@ embedded in larger data structures and replace fields they duplicate. struct kobject { const char * k_name; - char name[KOBJ_NAME_LEN]; struct kref kref; struct list_head entry; struct kobject * parent; @@ -223,18 +222,15 @@ decl_subsys(devices, &ktype_device, &device_uevent_ops); is equivalent to doing: struct kset devices_subsys = { - .kobj = { - .name = "devices", - }, .ktype = &ktype_devices, .uevent_ops = &device_uevent_ops, }; - +kobject_set_name(&devices_subsys, name); The objects that are registered with a subsystem that use the subsystem's default list must have their kset ptr set properly. These objects may have embedded kobjects or ksets. The -following helpers make setting the kset easier: +following helper makes setting the kset easier: kobj_set_kset_s(obj,subsys) @@ -242,22 +238,8 @@ kobj_set_kset_s(obj,subsys) - Assumes that obj->kobj exists, and is a struct kobject. - Sets the kset of that kobject to the kset <subsys>. - -kset_set_kset_s(obj,subsys) - -- Assumes that obj->kset exists, and is a struct kset. -- Sets the kset of the embedded kobject to the kset <subsys>. - -subsys_set_kset(obj,subsys) - -- Assumes obj->subsys exists, and is a struct subsystem. -- Sets obj->subsys.kset.kobj.kset to the subsystem's embedded kset. - -void subsystem_init(struct kset *s); int subsystem_register(struct kset *s); void subsystem_unregister(struct kset *s); -struct kset *subsys_get(struct kset *s); -void kset_put(struct kset *s); These are just wrappers around the respective kset_* functions. diff --git a/Documentation/s390/00-INDEX b/Documentation/s390/00-INDEX new file mode 100644 index 0000000..3a2b963 --- /dev/null +++ b/Documentation/s390/00-INDEX @@ -0,0 +1,26 @@ +00-INDEX + - this file. +3270.ChangeLog + - ChangeLog for the UTS Global 3270-support patch (outdated). +3270.txt + - how to use the IBM 3270 display system support. +cds.txt + - s390 common device support (common I/O layer). +CommonIO + - common I/O layer command line parameters, procfs and debugfs entries +config3270.sh + - example configuration for 3270 devices. +DASD + - information on the DASD disk device driver. +Debugging390.txt + - hints for debugging on s390 systems. +driver-model.txt + - information on s390 devices and the driver model. +monreader.txt + - information on accessing the z/VM monitor stream from Linux. +s390dbf.txt + - information on using the s390 debug feature. +TAPE + - information on the driver for channel-attached tapes. +zfcpdump + - information on the s390 SCSI dump tool. diff --git a/Documentation/s390/CommonIO b/Documentation/s390/CommonIO index 22f82f2..86320aa 100644 --- a/Documentation/s390/CommonIO +++ b/Documentation/s390/CommonIO @@ -1,5 +1,5 @@ -S/390 common I/O-Layer - command line parameters and /proc entries -================================================================== +S/390 common I/O-Layer - command line parameters, procfs and debugfs entries +============================================================================ Command line parameters ----------------------- @@ -7,9 +7,9 @@ Command line parameters * cio_msg = yes | no Determines whether information on found devices and sensed device - characteristics should be shown during startup, i. e. messages of the types - "Detected device 0.0.4711 on subchannel 0.0.0042" and "SenseID: Device - 0.0.4711 reports: ...". + characteristics should be shown during startup or when new devices are + found, i. e. messages of the types "Detected device 0.0.4711 on subchannel + 0.0.0042" and "SenseID: Device 0.0.4711 reports: ...". Default is off. @@ -26,8 +26,10 @@ Command line parameters An ignored device can be un-ignored later; see the "/proc entries"-section for details. - The devices must be given either as bus ids (0.0.abcd) or as hexadecimal - device numbers (0xabcd or abcd, for 2.4 backward compatibility). + The devices must be given either as bus ids (0.x.abcd) or as hexadecimal + device numbers (0xabcd or abcd, for 2.4 backward compatibility). If you + give a device number 0xabcd, it will be interpreted as 0.0.abcd. + You can use the 'all' keyword to ignore all devices. The '!' operator will cause the I/O-layer to _not_ ignore a device. The command line is parsed from left to right. @@ -81,31 +83,36 @@ Command line parameters will add 0.0.a000-0.0.accc and 0.0.af00-0.0.afff to the list of ignored devices. - The devices can be specified either by bus id (0.0.abcd) or, for 2.4 backward - compatibility, by the device number in hexadecimal (0xabcd or abcd). + The devices can be specified either by bus id (0.x.abcd) or, for 2.4 backward + compatibility, by the device number in hexadecimal (0xabcd or abcd). Device + numbers given as 0xabcd will be interpreted as 0.0.abcd. + +* For some of the information present in the /proc filesystem in 2.4 (namely, + /proc/subchannels and /proc/chpids), see driver-model.txt. + Information formerly in /proc/irq_count is now in /proc/interrupts. + +debugfs entries +--------------- -* /proc/s390dbf/cio_*/ (S/390 debug feature) +* /sys/kernel/debug/s390dbf/cio_*/ (S/390 debug feature) Some views generated by the debug feature to hold various debug outputs. - - /proc/s390dbf/cio_crw/sprintf + - /sys/kernel/debug/s390dbf/cio_crw/sprintf Messages from the processing of pending channel report words (machine check - handling), which will also show when CONFIG_DEBUG_CRW is defined. + handling). - - /proc/s390dbf/cio_msg/sprintf - Various debug messages from the common I/O-layer; generally, messages which - will also show when CONFIG_DEBUG_IO is defined. + - /sys/kernel/debug/s390dbf/cio_msg/sprintf + Various debug messages from the common I/O-layer, including messages + printed when cio_msg=yes. - - /proc/s390dbf/cio_trace/hex_ascii + - /sys/kernel/debug/s390dbf/cio_trace/hex_ascii Logs the calling of functions in the common I/O-layer and, if applicable, which subchannel they were called for, as well as dumps of some data structures (like irb in an error case). The level of logging can be changed to be more or less verbose by piping to - /proc/s390dbf/cio_*/level a number between 0 and 6; see the documentation on - the S/390 debug feature (Documentation/s390/s390dbf.txt) for details. - -* For some of the information present in the /proc filesystem in 2.4 (namely, - /proc/subchannels and /proc/chpids), see driver-model.txt. - Information formerly in /proc/irq_count is now in /proc/interrupts. + /sys/kernel/debug/s390dbf/cio_*/level a number between 0 and 6; see the + documentation on the S/390 debug feature (Documentation/s390/s390dbf.txt) + for details. diff --git a/Documentation/s390/cds.txt b/Documentation/s390/cds.txt index 58919d6..3081927 100644 --- a/Documentation/s390/cds.txt +++ b/Documentation/s390/cds.txt @@ -286,10 +286,10 @@ first: timeout value -EIO: the common I/O layer terminated the request due to an error state -If the concurrent sense flag in the extended status word in the irb is set, the -field irb->scsw.count describes the number of device specific sense bytes -available in the extended control word irb->scsw.ecw[0]. No device sensing by -the device driver itself is required. +If the concurrent sense flag in the extended status word (esw) in the irb is +set, the field erw.scnt in the esw describes the number of device specific +sense bytes available in the extended control word irb->scsw.ecw[]. No device +sensing by the device driver itself is required. The device interrupt handler can use the following definitions to investigate the primary unit check source coded in sense byte 0 : diff --git a/Documentation/usb/authorization.txt b/Documentation/usb/authorization.txt new file mode 100644 index 0000000..2af4006 --- /dev/null +++ b/Documentation/usb/authorization.txt @@ -0,0 +1,92 @@ + +Authorizing (or not) your USB devices to connect to the system + +(C) 2007 Inaky Perez-Gonzalez <inaky@linux.intel.com> Intel Corporation + +This feature allows you to control if a USB device can be used (or +not) in a system. This feature will allow you to implement a lock-down +of USB devices, fully controlled by user space. + +As of now, when a USB device is connected it is configured and +it's interfaces inmediately made available to the users. With this +modification, only if root authorizes the device to be configured will +then it be possible to use it. + +Usage: + +Authorize a device to connect: + +$ echo 1 > /sys/usb/devices/DEVICE/authorized + +Deauthorize a device: + +$ echo 0 > /sys/usb/devices/DEVICE/authorized + +Set new devices connected to hostX to be deauthorized by default (ie: +lock down): + +$ echo 0 > /sys/bus/devices/usbX/authorized_default + +Remove the lock down: + +$ echo 1 > /sys/bus/devices/usbX/authorized_default + +By default, Wired USB devices are authorized by default to +connect. Wireless USB hosts deauthorize by default all new connected +devices (this is so because we need to do an authentication phase +before authorizing). + + +Example system lockdown (lame) +----------------------- + +Imagine you want to implement a lockdown so only devices of type XYZ +can be connected (for example, it is a kiosk machine with a visible +USB port): + +boot up +rc.local -> + + for host in /sys/bus/devices/usb* + do + echo 0 > $host/authorized_default + done + +Hookup an script to udev, for new USB devices + + if device_is_my_type $DEV + then + echo 1 > $device_path/authorized + done + + +Now, device_is_my_type() is where the juice for a lockdown is. Just +checking if the class, type and protocol match something is the worse +security verification you can make (or the best, for someone willing +to break it). If you need something secure, use crypto and Certificate +Authentication or stuff like that. Something simple for an storage key +could be: + +function device_is_my_type() +{ + echo 1 > authorized # temporarily authorize it + # FIXME: make sure none can mount it + mount DEVICENODE /mntpoint + sum=$(md5sum /mntpoint/.signature) + if [ $sum = $(cat /etc/lockdown/keysum) ] + then + echo "We are good, connected" + umount /mntpoint + # Other stuff so others can use it + else + echo 0 > authorized + fi +} + + +Of course, this is lame, you'd want to do a real certificate +verification stuff with PKI, so you don't depend on a shared secret, +etc, but you get the idea. Anybody with access to a device gadget kit +can fake descriptors and device info. Don't trust that. You are +welcome. + diff --git a/Documentation/usb/power-management.txt b/Documentation/usb/power-management.txt new file mode 100644 index 0000000..97842de --- /dev/null +++ b/Documentation/usb/power-management.txt @@ -0,0 +1,517 @@ + Power Management for USB + + Alan Stern <stern@rowland.harvard.edu> + + October 5, 2007 + + + + What is Power Management? + ------------------------- + +Power Management (PM) is the practice of saving energy by suspending +parts of a computer system when they aren't being used. While a +component is "suspended" it is in a nonfunctional low-power state; it +might even be turned off completely. A suspended component can be +"resumed" (returned to a functional full-power state) when the kernel +needs to use it. (There also are forms of PM in which components are +placed in a less functional but still usable state instead of being +suspended; an example would be reducing the CPU's clock rate. This +document will not discuss those other forms.) + +When the parts being suspended include the CPU and most of the rest of +the system, we speak of it as a "system suspend". When a particular +device is turned off while the system as a whole remains running, we +call it a "dynamic suspend" (also known as a "runtime suspend" or +"selective suspend"). This document concentrates mostly on how +dynamic PM is implemented in the USB subsystem, although system PM is +covered to some extent (see Documentation/power/*.txt for more +information about system PM). + +Note: Dynamic PM support for USB is present only if the kernel was +built with CONFIG_USB_SUSPEND enabled. System PM support is present +only if the kernel was built with CONFIG_SUSPEND or CONFIG_HIBERNATION +enabled. + + + What is Remote Wakeup? + ---------------------- + +When a device has been suspended, it generally doesn't resume until +the computer tells it to. Likewise, if the entire computer has been +suspended, it generally doesn't resume until the user tells it to, say +by pressing a power button or opening the cover. + +However some devices have the capability of resuming by themselves, or +asking the kernel to resume them, or even telling the entire computer +to resume. This capability goes by several names such as "Wake On +LAN"; we will refer to it generically as "remote wakeup". When a +device is enabled for remote wakeup and it is suspended, it may resume +itself (or send a request to be resumed) in response to some external +event. Examples include a suspended keyboard resuming when a key is +pressed, or a suspended USB hub resuming when a device is plugged in. + + + When is a USB device idle? + -------------------------- + +A device is idle whenever the kernel thinks it's not busy doing +anything important and thus is a candidate for being suspended. The +exact definition depends on the device's driver; drivers are allowed +to declare that a device isn't idle even when there's no actual +communication taking place. (For example, a hub isn't considered idle +unless all the devices plugged into that hub are already suspended.) +In addition, a device isn't considered idle so long as a program keeps +its usbfs file open, whether or not any I/O is going on. + +If a USB device has no driver, its usbfs file isn't open, and it isn't +being accessed through sysfs, then it definitely is idle. + + + Forms of dynamic PM + ------------------- + +Dynamic suspends can occur in two ways: manual and automatic. +"Manual" means that the user has told the kernel to suspend a device, +whereas "automatic" means that the kernel has decided all by itself to +suspend a device. Automatic suspend is called "autosuspend" for +short. In general, a device won't be autosuspended unless it has been +idle for some minimum period of time, the so-called idle-delay time. + +Of course, nothing the kernel does on its own initiative should +prevent the computer or its devices from working properly. If a +device has been autosuspended and a program tries to use it, the +kernel will automatically resume the device (autoresume). For the +same reason, an autosuspended device will usually have remote wakeup +enabled, if the device supports remote wakeup. + +It is worth mentioning that many USB drivers don't support +autosuspend. In fact, at the time of this writing (Linux 2.6.23) the +only drivers which do support it are the hub driver, kaweth, asix, +usblp, usblcd, and usb-skeleton (which doesn't count). If a +non-supporting driver is bound to a device, the device won't be +autosuspended. In effect, the kernel pretends the device is never +idle. + +We can categorize power management events in two broad classes: +external and internal. External events are those triggered by some +agent outside the USB stack: system suspend/resume (triggered by +userspace), manual dynamic suspend/resume (also triggered by +userspace), and remote wakeup (triggered by the device). Internal +events are those triggered within the USB stack: autosuspend and +autoresume. + + + The user interface for dynamic PM + --------------------------------- + +The user interface for controlling dynamic PM is located in the power/ +subdirectory of each USB device's sysfs directory, that is, in +/sys/bus/usb/devices/.../power/ where "..." is the device's ID. The +relevant attribute files are: wakeup, level, and autosuspend. + + power/wakeup + + This file is empty if the device does not support + remote wakeup. Otherwise the file contains either the + word "enabled" or the word "disabled", and you can + write those words to the file. The setting determines + whether or not remote wakeup will be enabled when the + device is next suspended. (If the setting is changed + while the device is suspended, the change won't take + effect until the following suspend.) + + power/level + + This file contains one of three words: "on", "auto", + or "suspend". You can write those words to the file + to change the device's setting. + + "on" means that the device should be resumed and + autosuspend is not allowed. (Of course, system + suspends are still allowed.) + + "auto" is the normal state in which the kernel is + allowed to autosuspend and autoresume the device. + + "suspend" means that the device should remain + suspended, and autoresume is not allowed. (But remote + wakeup may still be allowed, since it is controlled + separately by the power/wakeup attribute.) + + power/autosuspend + + This file contains an integer value, which is the + number of seconds the device should remain idle before + the kernel will autosuspend it (the idle-delay time). + The default is 2. 0 means to autosuspend as soon as + the device becomes idle, and -1 means never to + autosuspend. You can write a number to the file to + change the autosuspend idle-delay time. + +Writing "-1" to power/autosuspend and writing "on" to power/level do +essentially the same thing -- they both prevent the device from being +autosuspended. Yes, this is a redundancy in the API. + +(In 2.6.21 writing "0" to power/autosuspend would prevent the device +from being autosuspended; the behavior was changed in 2.6.22. The +power/autosuspend attribute did not exist prior to 2.6.21, and the +power/level attribute did not exist prior to 2.6.22.) + + + Changing the default idle-delay time + ------------------------------------ + +The default autosuspend idle-delay time is controlled by a module +parameter in usbcore. You can specify the value when usbcore is +loaded. For example, to set it to 5 seconds instead of 2 you would +do: + + modprobe usbcore autosuspend=5 + +Equivalently, you could add to /etc/modprobe.conf a line saying: + + options usbcore autosuspend=5 + +Some distributions load the usbcore module very early during the boot +process, by means of a program or script running from an initramfs +image. To alter the parameter value you would have to rebuild that +image. + +If usbcore is compiled into the kernel rather than built as a loadable +module, you can add + + usbcore.autosuspend=5 + +to the kernel's boot command line. + +Finally, the parameter value can be changed while the system is +running. If you do: + + echo 5 >/sys/module/usbcore/parameters/autosuspend + +then each new USB device will have its autosuspend idle-delay +initialized to 5. (The idle-delay values for already existing devices +will not be affected.) + +Setting the initial default idle-delay to -1 will prevent any +autosuspend of any USB device. This is a simple alternative to +disabling CONFIG_USB_SUSPEND and rebuilding the kernel, and it has the +added benefit of allowing you to enable autosuspend for selected +devices. + + + Warnings + -------- + +The USB specification states that all USB devices must support power +management. Nevertheless, the sad fact is that many devices do not +support it very well. You can suspend them all right, but when you +try to resume them they disconnect themselves from the USB bus or +they stop working entirely. This seems to be especially prevalent +among printers and scanners, but plenty of other types of device have +the same deficiency. + +For this reason, by default the kernel disables autosuspend (the +power/level attribute is initialized to "on") for all devices other +than hubs. Hubs, at least, appear to be reasonably well-behaved in +this regard. + +(In 2.6.21 and 2.6.22 this wasn't the case. Autosuspend was enabled +by default for almost all USB devices. A number of people experienced +problems as a result.) + +This means that non-hub devices won't be autosuspended unless the user +or a program explicitly enables it. As of this writing there aren't +any widespread programs which will do this; we hope that in the near +future device managers such as HAL will take on this added +responsibility. In the meantime you can always carry out the +necessary operations by hand or add them to a udev script. You can +also change the idle-delay time; 2 seconds is not the best choice for +every device. + +Sometimes it turns out that even when a device does work okay with +autosuspend there are still problems. For example, there are +experimental patches adding autosuspend support to the usbhid driver, +which manages keyboards and mice, among other things. Tests with a +number of keyboards showed that typing on a suspended keyboard, while +causing the keyboard to do a remote wakeup all right, would +nonetheless frequently result in lost keystrokes. Tests with mice +showed that some of them would issue a remote-wakeup request in +response to button presses but not to motion, and some in response to +neither. + +The kernel will not prevent you from enabling autosuspend on devices +that can't handle it. It is even possible in theory to damage a +device by suspending it at the wrong time -- for example, suspending a +USB hard disk might cause it to spin down without parking the heads. +(Highly unlikely, but possible.) Take care. + + + The driver interface for Power Management + ----------------------------------------- + +The requirements for a USB driver to support external power management +are pretty modest; the driver need only define + + .suspend + .resume + .reset_resume + +methods in its usb_driver structure, and the reset_resume method is +optional. The methods' jobs are quite simple: + + The suspend method is called to warn the driver that the + device is going to be suspended. If the driver returns a + negative error code, the suspend will be aborted. Normally + the driver will return 0, in which case it must cancel all + outstanding URBs (usb_kill_urb()) and not submit any more. + + The resume method is called to tell the driver that the + device has been resumed and the driver can return to normal + operation. URBs may once more be submitted. + + The reset_resume method is called to tell the driver that + the device has been resumed and it also has been reset. + The driver should redo any necessary device initialization, + since the device has probably lost most or all of its state + (although the interfaces will be in the same altsettings as + before the suspend). + +The reset_resume method is used by the USB Persist facility (see +Documentation/usb/persist.txt) and it can also be used under certain +circumstances when CONFIG_USB_PERSIST is not enabled. Currently, if a +device is reset during a resume and the driver does not have a +reset_resume method, the driver won't receive any notification about +the resume. Later kernels will call the driver's disconnect method; +2.6.23 doesn't do this. + +USB drivers are bound to interfaces, so their suspend and resume +methods get called when the interfaces are suspended or resumed. In +principle one might want to suspend some interfaces on a device (i.e., +force the drivers for those interface to stop all activity) without +suspending the other interfaces. The USB core doesn't allow this; all +interfaces are suspended when the device itself is suspended and all +interfaces are resumed when the device is resumed. It isn't possible +to suspend or resume some but not all of a device's interfaces. The +closest you can come is to unbind the interfaces' drivers. + + + The driver interface for autosuspend and autoresume + --------------------------------------------------- + +To support autosuspend and autoresume, a driver should implement all +three of the methods listed above. In addition, a driver indicates +that it supports autosuspend by setting the .supports_autosuspend flag +in its usb_driver structure. It is then responsible for informing the +USB core whenever one of its interfaces becomes busy or idle. The +driver does so by calling these three functions: + + int usb_autopm_get_interface(struct usb_interface *intf); + void usb_autopm_put_interface(struct usb_interface *intf); + int usb_autopm_set_interface(struct usb_interface *intf); + +The functions work by maintaining a counter in the usb_interface +structure. When intf->pm_usage_count is > 0 then the interface is +deemed to be busy, and the kernel will not autosuspend the interface's +device. When intf->pm_usage_count is <= 0 then the interface is +considered to be idle, and the kernel may autosuspend the device. + +(There is a similar pm_usage_count field in struct usb_device, +associated with the device itself rather than any of its interfaces. +This field is used only by the USB core.) + +The driver owns intf->pm_usage_count; it can modify the value however +and whenever it likes. A nice aspect of the usb_autopm_* routines is +that the changes they make are protected by the usb_device structure's +PM mutex (udev->pm_mutex); however drivers may change pm_usage_count +without holding the mutex. + + usb_autopm_get_interface() increments pm_usage_count and + attempts an autoresume if the new value is > 0 and the + device is suspended. + + usb_autopm_put_interface() decrements pm_usage_count and + attempts an autosuspend if the new value is <= 0 and the + device isn't suspended. + + usb_autopm_set_interface() leaves pm_usage_count alone. + It attempts an autoresume if the value is > 0 and the device + is suspended, and it attempts an autosuspend if the value is + <= 0 and the device isn't suspended. + +There also are a couple of utility routines drivers can use: + + usb_autopm_enable() sets pm_usage_cnt to 1 and then calls + usb_autopm_set_interface(), which will attempt an autoresume. + + usb_autopm_disable() sets pm_usage_cnt to 0 and then calls + usb_autopm_set_interface(), which will attempt an autosuspend. + +The conventional usage pattern is that a driver calls +usb_autopm_get_interface() in its open routine and +usb_autopm_put_interface() in its close or release routine. But +other patterns are possible. + +The autosuspend attempts mentioned above will often fail for one +reason or another. For example, the power/level attribute might be +set to "on", or another interface in the same device might not be +idle. This is perfectly normal. If the reason for failure was that +the device hasn't been idle for long enough, a delayed workqueue +routine is automatically set up to carry out the operation when the +autosuspend idle-delay has expired. + +Autoresume attempts also can fail. This will happen if power/level is +set to "suspend" or if the device doesn't manage to resume properly. +Unlike autosuspend, there's no delay for an autoresume. + + + Other parts of the driver interface + ----------------------------------- + +Sometimes a driver needs to make sure that remote wakeup is enabled +during autosuspend. For example, there's not much point +autosuspending a keyboard if the user can't cause the keyboard to do a +remote wakeup by typing on it. If the driver sets +intf->needs_remote_wakeup to 1, the kernel won't autosuspend the +device if remote wakeup isn't available or has been disabled through +the power/wakeup attribute. (If the device is already autosuspended, +though, setting this flag won't cause the kernel to autoresume it. +Normally a driver would set this flag in its probe method, at which +time the device is guaranteed not to be autosuspended.) + +The usb_autopm_* routines have to run in a sleepable process context; +they must not be called from an interrupt handler or while holding a +spinlock. In fact, the entire autosuspend mechanism is not well geared +toward interrupt-driven operation. However there is one thing a +driver can do in an interrupt handler: + + usb_mark_last_busy(struct usb_device *udev); + +This sets udev->last_busy to the current time. udev->last_busy is the +field used for idle-delay calculations; updating it will cause any +pending autosuspend to be moved back. The usb_autopm_* routines will +also set the last_busy field to the current time. + +Calling urb_mark_last_busy() from within an URB completion handler is +subject to races: The kernel may have just finished deciding the +device has been idle for long enough but not yet gotten around to +calling the driver's suspend method. The driver would have to be +responsible for synchronizing its suspend method with its URB +completion handler and causing the autosuspend to fail with -EBUSY if +an URB had completed too recently. + +External suspend calls should never be allowed to fail in this way, +only autosuspend calls. The driver can tell them apart by checking +udev->auto_pm; this flag will be set to 1 for internal PM events +(autosuspend or autoresume) and 0 for external PM events. + +Many of the ingredients in the autosuspend framework are oriented +towards interfaces: The usb_interface structure contains the +pm_usage_cnt field, and the usb_autopm_* routines take an interface +pointer as their argument. But somewhat confusingly, a few of the +pieces (usb_mark_last_busy() and udev->auto_pm) use the usb_device +structure instead. Drivers need to keep this straight; they can call +interface_to_usbdev() to find the device structure for a given +interface. + + + Locking requirements + -------------------- + +All three suspend/resume methods are always called while holding the +usb_device's PM mutex. For external events -- but not necessarily for +autosuspend or autoresume -- the device semaphore (udev->dev.sem) will +also be held. This implies that external suspend/resume events are +mutually exclusive with calls to probe, disconnect, pre_reset, and +post_reset; the USB core guarantees that this is true of internal +suspend/resume events as well. + +If a driver wants to block all suspend/resume calls during some +critical section, it can simply acquire udev->pm_mutex. +Alternatively, if the critical section might call some of the +usb_autopm_* routines, the driver can avoid deadlock by doing: + + down(&udev->dev.sem); + rc = usb_autopm_get_interface(intf); + +and at the end of the critical section: + + if (!rc) + usb_autopm_put_interface(intf); + up(&udev->dev.sem); + +Holding the device semaphore will block all external PM calls, and the +usb_autopm_get_interface() will prevent any internal PM calls, even if +it fails. (Exercise: Why?) + +The rules for locking order are: + + Never acquire any device semaphore while holding any PM mutex. + + Never acquire udev->pm_mutex while holding the PM mutex for + a device that isn't a descendant of udev. + +In other words, PM mutexes should only be acquired going up the device +tree, and they should be acquired only after locking all the device +semaphores you need to hold. These rules don't matter to drivers very +much; they usually affect just the USB core. + +Still, drivers do need to be careful. For example, many drivers use a +private mutex to synchronize their normal I/O activities with their +disconnect method. Now if the driver supports autosuspend then it +must call usb_autopm_put_interface() from somewhere -- maybe from its +close method. It should make the call while holding the private mutex, +since a driver shouldn't call any of the usb_autopm_* functions for an +interface from which it has been unbound. + +But the usb_autpm_* routines always acquire the device's PM mutex, and +consequently the locking order has to be: private mutex first, PM +mutex second. Since the suspend method is always called with the PM +mutex held, it mustn't try to acquire the private mutex. It has to +synchronize with the driver's I/O activities in some other way. + + + Interaction between dynamic PM and system PM + -------------------------------------------- + +Dynamic power management and system power management can interact in +a couple of ways. + +Firstly, a device may already be manually suspended or autosuspended +when a system suspend occurs. Since system suspends are supposed to +be as transparent as possible, the device should remain suspended +following the system resume. The 2.6.23 kernel obeys this principle +for manually suspended devices but not for autosuspended devices; they +do get resumed when the system wakes up. (Presumably they will be +autosuspended again after their idle-delay time expires.) In later +kernels this behavior will be fixed. + +(There is an exception. If a device would undergo a reset-resume +instead of a normal resume, and the device is enabled for remote +wakeup, then the reset-resume takes place even if the device was +already suspended when the system suspend began. The justification is +that a reset-resume is a kind of remote-wakeup event. Or to put it +another way, a device which needs a reset won't be able to generate +normal remote-wakeup signals, so it ought to be resumed immediately.) + +Secondly, a dynamic power-management event may occur as a system +suspend is underway. The window for this is short, since system +suspends don't take long (a few seconds usually), but it can happen. +For example, a suspended device may send a remote-wakeup signal while +the system is suspending. The remote wakeup may succeed, which would +cause the system suspend to abort. If the remote wakeup doesn't +succeed, it may still remain active and thus cause the system to +resume as soon as the system suspend is complete. Or the remote +wakeup may fail and get lost. Which outcome occurs depends on timing +and on the hardware and firmware design. + +More interestingly, a device might undergo a manual resume or +autoresume during system suspend. With current kernels this shouldn't +happen, because manual resumes must be initiated by userspace and +autoresumes happen in response to I/O requests, but all user processes +and I/O should be quiescent during a system suspend -- thanks to the +freezer. However there are plans to do away with the freezer, which +would mean these things would become possible. If and when this comes +about, the USB core will carefully arrange matters so that either type +of resume will block until the entire system has resumed. diff --git a/Documentation/usb/usb-serial.txt b/Documentation/usb/usb-serial.txt index 5b635ae..4e0b62b 100644 --- a/Documentation/usb/usb-serial.txt +++ b/Documentation/usb/usb-serial.txt @@ -428,6 +428,17 @@ Options supported: See http://www.uuhaus.de/linux/palmconnect.html for up-to-date information on this driver. +Winchiphead CH341 Driver + + This driver is for the Winchiphead CH341 USB-RS232 Converter. This chip + also implements an IEEE 1284 parallel port, I2C and SPI, but that is not + supported by the driver. The protocol was analyzed from the behaviour + of the Windows driver, no datasheet is available at present. + The manufacturer's website: http://www.winchiphead.com/. + For any questions or problems with this driver, please contact + frank@kingswood-consulting.co.uk. + + Generic Serial driver If your device is not one of the above listed devices, compatible with diff --git a/Documentation/usb/usbmon.txt b/Documentation/usb/usbmon.txt index 53ae866a..2917ce4 100644 --- a/Documentation/usb/usbmon.txt +++ b/Documentation/usb/usbmon.txt @@ -34,9 +34,12 @@ if usbmon is built into the kernel. Verify that bus sockets are present. # ls /sys/kernel/debug/usbmon -1s 1t 1u 2s 2t 2u 3s 3t 3u 4s 4t 4u +0s 0t 0u 1s 1t 1u 2s 2t 2u 3s 3t 3u 4s 4t 4u # +Now you can choose to either use the sockets numbered '0' (to capture packets on +all buses), and skip to step #3, or find the bus used by your device with step #2. + 2. Find which bus connects to the desired device Run "cat /proc/bus/usb/devices", and find the T-line which corresponds to @@ -56,6 +59,10 @@ Bus=03 means it's bus 3. # cat /sys/kernel/debug/usbmon/3u > /tmp/1.mon.out +to listen on a single bus, otherwise, to listen on all buses, type: + +# cat /sys/kernel/debug/usbmon/0u > /tmp/1.mon.out + This process will be reading until killed. Naturally, the output can be redirected to a desirable location. This is preferred, because it is going to be quite long. |