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On some SoCs (like exynos5250) you need to use an external GPIO for
write protect. Add support for wp-gpios to the core dw_mmc driver
since it could be useful across multiple SoCs.
With this change I am able to make use of the write protect for the
external SD slot on exynos5250-snow.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
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The exynos code claimed the write protect with devm_gpio_request() but
never did anything with it. That meant that anyone using a write
protect GPIO would effectively be write protected all the time.
The handling for wp-gpios belongs in the main dw_mmc driver and has
been moved there.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
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The next change will remove the code from the dw_mmc-exynos that added
the DW_MCI_QUIRK_NO_WRITE_PROTECT. Keep existing functionality of
having no write protect pin on smdk5250 by adding the disable-wp
property.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
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The "disable-wp" property is used to specify that a given SD card slot
doesn't have a concept of write protect. This eliminates the need for
special case code for SD slots that should never be write protected
(like a micro SD slot or a dev board).
The dw_mmc driver is special in needing to specify "disable-wp"
because the lack of a "wp-gpios" property means to use the special
purpose write protect line. On some other mmc devices the lack of
"wp-gpios" means that write protect should be disabled.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Acked-by: Seungwon Jeon <tgih.jun@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
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The right value is 54 according to eMMC 4.5 specification.
Signed-off-by: ZhangYi <yix.x.zhang@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Fixes the following warning when building with W=1 option:
drivers/mmc/host/mxs-mmc.c: In function 'mxs_mmc_adtc':
drivers/mmc/host/mxs-mmc.c:401:2: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
The warning happens because 'i' is used in 'for_each_sg(sgl, sg, sg_len, i)' and should be made unsigned.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Add an entry for MODULE_ALIAS().
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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On many Marvell SoCs, the pins used for the SDIO interface are part of
the MPP pins, that are muxable pins. In order to get the muxing of
those pins correct, this commit integrates the mvsdio driver with the
pinctrl infrastructure by calling devm_pinctrl_get_select_default()
during ->probe().
Note that we permit this function to fail because not all Marvell
platforms have yet been fully converted to using the pinctrl
infrastructure.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Stefan Peter <s.peter@mpl.ch>
Tested-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
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This patch adds a simple Device Tree binding for the mvsdio driver, as
well as the necessary documentation for it. Compatibility with non-DT
platforms is preserved, by keeping the platform_data based
initialization.
We introduce a small difference between non-DT and DT platforms: DT
platforms are required to provide a clocks = <...> property, which the
driver uses to get the frequency of the clock that goes to the SDIO
IP. The behaviour on non-DT platforms is kept unchanged: a clock
reference is not mandatory, but the clock frequency must be passed in
the "clock" field of the mvsdio_platform_data structure.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Stefan Peter <s.peter@mpl.ch>
Tested-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
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The MMC core subsystem provides in drivers/mmc/core/slot-gpio.c a nice
set of helper functions to simplify the management of the card detect
GPIO in MMC host drivers. This patch migrates the mvsdio driver to
using those helpers, which will make the ->probe() code simpler, and
therefore ease the process of adding a Device Tree binding for this
driver.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Stefan Peter <s.peter@mpl.ch>
Tested-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
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The MMC core subsystem provides in drivers/mmc/core/slot-gpio.c a nice
set of helper functions to simplify the management of the write
protect GPIO in MMC host drivers. This patch migrates the mvsdio
driver to using those helpers, which will make the ->probe() code
simpler, and therefore ease the process of adding a Device Tree
binding for this driver.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Stefan Peter <s.peter@mpl.ch>
Tested-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Chris Ball <cjb@laptop.org>
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With commit 9444e07 (mmc: remove unncessary mmc_gpio_free_cd() call from
slot-gpio users) in place, the ESDHC_CD_GPIO handling in IO accessories
becomes unnecessary. Remove it.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
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There are three places where same piece of code is used. Let's split it
to a separate function.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
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[cjb: The MMP3 architecture requires a registered interrupt to retire wfi
when waking from suspend.]
Signed-off-by: Jialing Fu <jlfu@marvell.com>
Signed-off-by: Kevin Liu <kliu5@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Don't disable SD Host IRQ during suspend if it is wake up source.
Enable wakeup event during suspend.
Signed-off-by: Jialing Fu <jlfu@marvell.com>
Signed-off-by: Kevin Liu <kliu5@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Current code missed disabling interrupts before free irq which is shared.
Notice below comments for function free_irq (kernel/irq/manage.c):
On a shared IRQ the caller must ensure the interrupt is disabled
on the card it drives before calling this function.
Original code has below issue during suspend/resume when multiple SD
hosts share the same IRQ:
1. Assume there are two hosts (host1 for emmc while host2 for sd) share
the same mmc irq.
2. When system suspend, host2 will be suspended before host1.
So the sequence is below:
step1: irq handler for host2 removed ->
step2: irq handler for host1 removed and irq disabled ->
... system suspended ...
... system resumed ...
step3: irq enabled and the irq handler for host1 restored ->
step4: irq handler for host2 restored
3. So there is the buggy time slot that the irq is enabled but the irq
handler for host2 is removed. Then host2 interrupt can be triggered
but can't be handled at that moment.
Signed-off-by: Jialing Fu <jlfu@marvell.com>
Signed-off-by: Kevin Liu <kliu5@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Add a very simple driver for the BCM2835 SoC, which is used in the
Raspberry Pi board.
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
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When current request is running on the bus and if next request fetched
by mmcqd is NULL, mmc context (mmcqd thread) gets blocked until the
current request completes. This means that if new request comes in while
the mmcqd thread is blocked, this new request can not be prepared in
parallel to current ongoing request. This may result in delaying the new
request execution and increase it's latency.
This change allows to wake up the MMC thread on new request arrival.
Now once the MMC thread is woken up, a new request can be fetched and
prepared in parallel to the current running request which means this new
request can be started immediately after the current running request
completes.
With this change read throughput is improved by 16%.
Signed-off-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Reviewed-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Unlike normal r/w request, special requests(discard, flush)
is finished with a one-time issue_fn. Request change to
mqrq_prev makes unnecessary call.
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Reviewed-by: Konstantin Dorfman <kdorfman@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
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The classical way to process IRQs is read out the status, ack all triggered
IRQs, possibly mask them, then process them. Follow this simple procesure
instead of the current complex custom algorithm.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Make error reporting in the driver more verbose. This patch is based on
an earlier work by Teppei Kamijou, but we try to not add any new error
messages to the log in the normal case to avoid confusing the user, and
also add a few more dev_dbg() calls.
Signed-off-by: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
[g.liakhovetski@gmx.de: avoid producing new errors in normal case]
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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The INT_BUFWEN IRQ often arrives with other bits set too. If they are not
cleared, an additional IRQ can be triggered, sometimes also after the MMC
request has already been completed. This leads to block I/O errors. Earlier
Teppei Kamijou also observed these additional interrupts and proposed to
explicitly wait for them. This patch chooses an alternative approach of
clearing all active bits immediately, when processing the main interrupt.
Reported-by: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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DMA completion can be signalled from the DMA callback and from the error
handler. If both are called, the completion struct can enter an
inconsistent state. To prevent this move completion initialisation
immediately before activating DMA.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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If a command execution has produced an error, it has to be reset as a part
of the error handling.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Oopses have been observed on SMP in the sh-mmcif IRQ thread, when the two
IRQ threads run simultaneously on two CPUs. Also take care to guard the
timeout work and the DMA completion callback from possible NULL-pointer
dereferences and races.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Use "return condition" instead of "if (condition) return true; return false"
in functions, returning bool.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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If a DMA transaction fails, terminate all outstanding DMA transfers and
unmap buffers.
Signed-off-by: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
[g.liakhovetski@gmx.de: forward-port, add dma_unmap_sg() in error cases]
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Read block and write block operations are currently missing completion
timeouts. Add missing timeouts and consolidate them at one location.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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SH/R-Mobile MMCIF host controller can wait while the card signals busy.
Set MMC_CAP_WAIT_WHILE_BUSY to inform an upper layer (core/mmc_ops.c)
not to insert unnecessary mmc_delay().
Signed-off-by: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Timeout period should be properly normalized using msecs_to_jiffies().
Signed-off-by: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Some MMCIF implementations support the Dual Data Rate. With this patch,
platforms can set the MMC_CAP_UHS_DDR50 capability flag in MMCIF platform
data. This will let the MMC core to actually use the DDR mode.
Signed-off-by: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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On newer SoCs like R-Mobile U2, MMCIF interrupts are bundled.
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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With this post-v2.6.35 change applied:
commit a0a1a5fd4fb15ec61117c759fe9f5c16c53d9e9c
Author: Tejun Heo <tj@kernel.org>
Date: Tue Jun 29 10:07:12 2010 +0200
workqueue: reimplement workqueue freeze using max_active
freeze_workqueues_begin() was introduced and workqueue now gets frozen
before device drivers suspend operations.
We have to ensure that run-time PM suspend operation completes before
system-wide suspend is started.
Signed-off-by: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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mmc_rescan() sends CMD52 (SD_IO_RW_DIRECT) to reset SDIO card during
card detection. CMD52 should be ignored by SD/eMMC cards, but we can
also abort it in the driver immediately, since MMCIF doesn't support
SDIO cards anyway.
Signed-off-by: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Use slot-gpio helpers to save some code in the driver.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Since slot-gpio uses devm_* managed functions in mmc_gpio_request_cd()
now, we can remove those mmc_gpio_free_cd() call from host drivers'
.probe() error path and .remove().
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Use devm_* managed functions, so that slot-gpio users do not have to
call mmc_gpio_free_ro/cd to free up resources requested in
mmc_gpio_request_ro/cd.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
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Call mmc_gpio_get_cd() to query card presence from cd-gpio before
asking SDHCI. The rationale behind this change is that flag
SDHCI_QUIRK_BROKEN_CARD_DETECTION is designed for SDHCI controller to
tell that SDHCI_PRESENT_STATE is broken, and it should be used for this
case only. So when cd-gpio is being used, the controller should set
the flag to tell that SDHCI_PRESENT_STATE is not available.
However, the existing code will skip checking cd-gpio as long as flag
SDHCI_QUIRK_BROKEN_CARD_DETECTION is set. Change the querying order
between cd-gpio and SDHCI to support the rationale above.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
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When SDIO3.0 card is detected, incorrect bus speed mode
is printed as part of card detection print in kernel logs.
This change fixes it so that user won't be confused by
looking at incorrect card detection message in logs.
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Tested-by: Jackey Shen <Jackey.Shen@amd.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
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According to UHS-I initialization sequence for SDIO 3.0 cards,
the host must set bit[24] (S18R) of OCR register during OCR
handshake to know whether the SDIO card is capable of doing
1.8V I/O.
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Johan Rudholm <johan.rudholm@stericsson.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
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If SDIO keep power flag (MMC_PM_KEEP_POWER) is not set, card would
be reinitialized during resume but as we are not resetting
(CMD52 reset) the SDIO card during this reinitialization, card may
fail to respond back to subsequent commands (CMD5 etc...).
This change resets the card before the reinitialization of card
during resume.
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
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digsig_verify_rsa() does not free kmalloc'ed buffer returned by
mpi_get_buffer().
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm
Pull more device-mapper fixes from Alasdair G Kergon:
"A fix for stacked dm thin devices and a fix for the new dm WRITE SAME
support."
* tag 'dm-3.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
dm: fix write same requests counting
dm thin: fix queue limits stacking
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git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
PullHID fixes from Jiri Kosina:
- fix i2c-hid and hidraw interaction, by Benjamin Tissoires
- a quirk to make a particular device (Formosa IR receiver) work
properly, by Nicholas Santos
* 'for-3.8/upstream-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: i2c-hid: fix i2c_hid_output_raw_report
HID: usbhid: quirk for Formosa IR receiver
HID: remove x bit from sensor doc
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Pull NFS client bugfixes from Trond Myklebust:
- Error reporting in nfs_xdev_mount incorrectly maps all errors to
ENOMEM
- Fix an NFSv4 refcounting issue
- Fix a mount failure when the server reboots during NFSv4 trunking
discovery
- NFSv4.1 mounts may need to run the lease recovery thread.
- Don't silently fail setattr() requests on mountpoints
- Fix a SUNRPC socket/transport livelock and priority queue issue
- We must handle NFS4ERR_DELAY when resetting the NFSv4.1 session.
* tag 'nfs-for-3.8-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
NFSv4.1: Handle NFS4ERR_DELAY when resetting the NFSv4.1 session
SUNRPC: When changing the queue priority, ensure that we change the owner
NFS: Don't silently fail setattr() requests on mountpoints
NFSv4.1: Ensure that nfs41_walk_client_list() does start lease recovery
NFSv4: Fix NFSv4 trunking discovery
NFSv4: Fix NFSv4 reference counting for trunked sessions
NFS: Fix error reporting in nfs_xdev_mount
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Pull MIPS updates from Ralf Baechle:
"A number of fixes all across the MIPS tree. No area is particularly
standing out and things have cooled down quite nicely for a release."
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: Function tracer: Fix broken function tracing
mips: Move __virt_addr_valid() to a place for MIPS 64
MIPS: Netlogic: Fix UP compilation on XLR
MIPS: AR71xx: Fix AR71XX_PCI_MEM_SIZE
MIPS: AR724x: Fix AR724X_PCI_MEM_SIZE
MIPS: Lantiq: Fix cp0_perfcount_irq mapping
MIPS: DSP: Fix DSP mask for registers.
MIPS: Fix build failure by adding definition of pfn_pmd().
MIPS: Octeon: Fix warning.
MIPS: delay.c: Check BITS_PER_LONG instead of __SIZEOF_LONG__
MIPS: PNX833x: Fix comment.
MIPS: Add struct p_format to union mips_instruction.
MIPS: Export <asm/break.h>.
MIPS: BCM47xx: Enable SSB prerequisite SSB_DRIVER_PCICORE.
MIPS: BCM47xx: Select GPIOLIB for BCMA on bcm47xx platform
MIPS: vpe.c: Fix null pointer dereference in print arguments.
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i2c_hid_output_raw_report is used by hidraw to forward set_report requests.
The current implementation of i2c_hid_set_report needs to take the
report_id as an argument. The report_id is stored in the first byte
of the buffer in argument of i2c_hid_output_raw_report.
Not removing the report_id from the given buffer adds this byte 2 times
in the command, leading to a non working command.
Reported-by: Andrew Duggan <aduggan@synaptics.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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Function tracing is currently broken for all 32 bit MIPS platforms.
When tracing is enabled, the kernel immediately hangs on boot.
This is a result of commit b732d439cb43336cd6d7e804ecb2c81193ef63b0
that changes the kernel/trace/Kconfig file so that is no longer
forces FRAME_POINTER when FUNCTION_TRACING is enabled.
MIPS frame pointers are generally considered to be useless because
they cannot be used to unwind the stack. Unfortunately the MIPS
function tracing code has bugs that are masked by the use of frame
pointers. This commit fixes the bugs so that MIPS frame pointers
don't need to be enabled.
The bugs are a result of the odd calling sequence used to call the trace
routine. This calling sequence is inserted into every traceable function
when the tracing CONFIG option is enabled. This sequence is generated
for 32bit MIPS platforms by the compiler via the "-pg" flag.
Part of the sequence is "addiu sp,sp,-8" in the delay slot after every
call to the trace routine "_mcount" (some legacy thing where 2 arguments
used to be pushed on the stack). The _mcount routine is expected to
adjust the sp by +8 before returning. So when not disabled, the original
jalr and addiu will be there, so _mcount has to adjust sp.
The problem is that when tracing is disabled for a function, the
"jalr _mcount" instruction is replaced with a nop, but the
"addiu sp,sp,-8" is still executed and the stack pointer is left
trashed. When frame pointers are enabled the problem is masked
because any access to the stack is done through the frame
pointer and the stack pointer is restored from the frame pointer when
the function returns.
This patch writes two nops starting at the address of the "jalr _mcount"
instruction whenever tracing is disabled. This means that the
"addiu sp,sp.-8" will be converted to a nop along with the "jalr". When
disabled, there will be two nops.
This is SMP safe because the first time this happens is during
ftrace_init() which is before any other processor has been started.
Subsequent calls to enable/disable tracing when other CPUs ARE running
will still be safe because the enable will only change the first nop
to a "jalr" and the disable, while writing 2 nops, will only be changing
the "jalr". This patch also stops using stop_machine() to call the
tracer enable/disable routines and calls them directly because the
routines are SMP safe.
When the kernel first boots we have to be able to handle the gcc
generated jalr, addui sequence until ftrace_init gets a chance to run
and change the sequence. At this point mcount just adjusts the stack
and returns. When ftrace_init runs, we convert the jalr/addui to nops.
Then whenever tracing is enabled we convert the first nop to a "jalr
mcount+8". The mcount+8 entry point skips the stack adjust.
[ralf@linux-mips.org: Folded in Steven Rostedt's build fix.]
Signed-off-by: Al Cooper <alcooperx@gmail.com>
Cc: rostedt@goodmis.org
Cc: ddaney.cavm@gmail.com
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/4806/
Patchwork: https://patchwork.linux-mips.org/patch/4841/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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When processing write same requests, fix dm to send the configured
number of WRITE SAME requests to the target rather than the number of
discards, which is not always the same.
Device-mapper WRITE SAME support was introduced by commit
23508a96cd2e857d57044a2ed7d305f2d9daf441 ("dm: add WRITE SAME support").
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
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