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path: root/drivers/char/apm-emulation.c
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2012-04-06Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/apm Pull an APM fix from Jiri Kosina: "One deadlock/race fix from Niel that got introduced when we were moving away from freezer_*_count() to wait_event_freezable()." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/apm: APM: fix deadlock in APM_IOC_SUSPEND ioctl
2012-04-03APM: fix deadlock in APM_IOC_SUSPEND ioctlNeilBrown
I found the Xorg server on my ARM device stuck in the 'msleep()' loop in apm_ioctl. I suspect it had attempted suspend immediately after resuming and lost a race. During that msleep(10);, a new suspend cycle must have started and changed ->suspend_state to SUSPEND_PENDING, so it was never seen to be SUSPEND_DONE and the loop could never exited. It would have moved on to SUSPEND_ACKTO but never been able to reach SUSPEND_DONE. So change the loop to only run while SUSPEND_ACKED rather than until SUSPEND_DONE. This is much safer. Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-03-28Remove all #inclusions of asm/system.hDavid Howells
Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
2011-10-25Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (59 commits) MAINTAINERS: linux-m32r is moderated for non-subscribers linux@lists.openrisc.net is moderated for non-subscribers Drop default from "DM365 codec select" choice parisc: Kconfig: cleanup Kernel page size default Kconfig: remove redundant CONFIG_ prefix on two symbols cris: remove arch/cris/arch-v32/lib/nand_init.S microblaze: add missing CONFIG_ prefixes h8300: drop puzzling Kconfig dependencies MAINTAINERS: microblaze-uclinux@itee.uq.edu.au is moderated for non-subscribers tty: drop superfluous dependency in Kconfig ARM: mxc: fix Kconfig typo 'i.MX51' Fix file references in Kconfig files aic7xxx: fix Kconfig references to READMEs Fix file references in drivers/ide/ thinkpad_acpi: Fix printk typo 'bluestooth' bcmring: drop commented out line in Kconfig btmrvl_sdio: fix typo 'btmrvl_sdio_sd6888' doc: raw1394: Trivial typo fix CIFS: Don't free volume_info->UNC until we are entirely done with it. treewide: Correct spelling of successfully in comments ...
2011-10-25Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/apm * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/apm: apm-emulation: use wait_event_freezable() instead of freezer_[do_not_]count()
2011-09-27doc: fix broken referencesPaul Bolle
There are numerous broken references to Documentation files (in other Documentation files, in comments, etc.). These broken references are caused by typo's in the references, and by renames or removals of the Documentation files. Some broken references are simply odd. Fix these broken references, sometimes by dropping the irrelevant text they were part of. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-08-23apm-emulation: use wait_event_freezable() instead of freezer_[do_not_]count()Tejun Heo
vfork is moving away from freezer_[do_not_]count() one way or the other leaving apm_ioctl() as the only user. apm_ioctl() just wants to wait for suspend/resume cycle to complete without hindering the freezer. Use wait_event_freezable() instead. The only annoyance is that wait_event_freezable() wakes up with -ERESTART if there are pending signals while apm_ioctl() wants to ignore all signals until suspend is complete. We can play with @current->[real_]blocked but this is hardly a performance or latency critical path - simply chill a bit on each iteration until SUSPEND_DONE for unlikely cases where there are pending signals. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-07-15PM: Improve error code of pm_notifier_call_chain()Akinobu Mita
This enables pm_notifier_call_chain() to get the actual error code in the callback rather than always assume -EINVAL by converting all PM notifier calls to return encapsulate error code with notifier_from_errno(). Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-05-23apm-emulation: apm_mutex breaks ACK; remove itPaul Parsons
apm_mutex is locked by a process (e.g. apm -s) at the start of apm_ioctl() and remains locked while pm_suspend() is called. Any subsequent process trying to ACK the suspend (e.g. apmd) is then blocked at the start of apm_ioctl(), causing the suspend to be delayed for 5 seconds in apm_suspend_notifier() while the ACK times out. In short, ACKs don't work. The driver's data structures are sufficiently protected by assorted locks. And pm_suspend() has its own mutex to prevent reentrancy. Consequently there is no obvious requirement for apm_mutex, which evolved from earlier BKL calls. So let's remove it. Signed-off-by: Paul Parsons <lost.distance@yahoo.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-10-24Merge branch 'for-next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) Update broken web addresses in arch directory. Update broken web addresses in the kernel. Revert "drivers/usb: Remove unnecessary return's from void functions" for musb gadget Revert "Fix typo: configuation => configuration" partially ida: document IDA_BITMAP_LONGS calculation ext2: fix a typo on comment in ext2/inode.c drivers/scsi: Remove unnecessary casts of private_data drivers/s390: Remove unnecessary casts of private_data net/sunrpc/rpc_pipe.c: Remove unnecessary casts of private_data drivers/infiniband: Remove unnecessary casts of private_data drivers/gpu/drm: Remove unnecessary casts of private_data kernel/pm_qos_params.c: Remove unnecessary casts of private_data fs/ecryptfs: Remove unnecessary casts of private_data fs/seq_file.c: Remove unnecessary casts of private_data arm: uengine.c: remove C99 comments arm: scoop.c: remove C99 comments Fix typo configue => configure in comments Fix typo: configuation => configuration Fix typo interrest[ing|ed] => interest[ing|ed] Fix various typos of valid in comments ... Fix up trivial conflicts in: drivers/char/ipmi/ipmi_si_intf.c drivers/usb/gadget/rndis.c net/irda/irnet/irnet_ppp.c
2010-10-22Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: vfs: make no_llseek the default vfs: don't use BKL in default_llseek llseek: automatically add .llseek fop libfs: use generic_file_llseek for simple_attr mac80211: disallow seeks in minstrel debug code lirc: make chardev nonseekable viotape: use noop_llseek raw: use explicit llseek file operations ibmasmfs: use generic_file_llseek spufs: use llseek in all file operations arm/omap: use generic_file_llseek in iommu_debug lkdtm: use generic_file_llseek in debugfs net/wireless: use generic_file_llseek in debugfs drm: use noop_llseek
2010-10-18Update broken web addresses in the kernel.Justin P. Mattock
The patch below updates broken web addresses in the kernel Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Finn Thain <fthain@telegraphics.com.au> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Dimitry Torokhov <dmitry.torokhov@gmail.com> Cc: Mike Frysinger <vapier.adi@gmail.com> Acked-by: Ben Pfaff <blp@cs.stanford.edu> Acked-by: Hans J. Koch <hjk@linutronix.de> Reviewed-by: Finn Thain <fthain@telegraphics.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-10-05drivers: autoconvert trivial BKL users to private mutexArnd Bergmann
All these files use the big kernel lock in a trivial way to serialize their private file operations, typically resulting from an earlier semi-automatic pushdown from VFS. None of these drivers appears to want to lock against other code, and they all use the BKL as the top-level lock in their file operations, meaning that there is no lock-order inversion problem. Consequently, we can remove the BKL completely, replacing it with a per-file mutex in every case. Using a scripted approach means we can avoid typos. These drivers do not seem to be under active maintainance from my brief investigation. Apologies to those maintainers that I have missed. file=$1 name=$2 if grep -q lock_kernel ${file} ; then if grep -q 'include.*linux.mutex.h' ${file} ; then sed -i '/include.*<linux\/smp_lock.h>/d' ${file} else sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file} fi sed -i ${file} \ -e "/^#include.*linux.mutex.h/,$ { 1,/^\(static\|int\|long\)/ { /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex); } }" \ -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \ -e '/[ ]*cycle_kernel_lock();/d' else sed -i -e '/include.*\<smp_lock.h\>/d' ${file} \ -e '/cycle_kernel_lock()/d' fi Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2010-05-17drivers: Push down BKL into various driversArnd Bergmann
These are the last remaining device drivers using the ->ioctl file operation in the drivers directory (except from v4l drivers). [fweisbec: drop i8k pushdown as it has been done from procfs pushdown branch already] Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-10-01const: constify remaining file_operationsAlexey Dobriyan
[akpm@linux-foundation.org: fix KVM] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-16APM emulation: Notify about all suspend events, not just APM invoked ones (v2)Johannes Berg
This revamps the apm-emulation code to get suspend notifications regardless of what way pm_suspend() was invoked, whether via the apm ioctl or via /sys/power/state. Also do some code cleanup and add comments while at it. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
2008-06-20apm-emulation: BKL pushdownArnd Bergmann
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2008-04-29proc: switch /proc/apm to seq_file interfaceAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Len Brown <len.brown@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-11-21Freezer: Fix APM emulation breakageRafael J. Wysocki
The APM emulation is currently broken as a result of commit 831441862956fffa17b9801db37e6ea1650b0f69 "Freezer: make kernel threads nonfreezable by default" that removed the PF_NOFREEZE annotations from apm_ioctl() without adding the appropriate freezer hooks. Fix it and remove the unnecessary variable flags from apm_ioctl(). Special thanks to Franck Bui-Huu <vagabon.xyz@gmail.com> for pointing out the problem. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Cc: Pavel Machek <pavel@ucw.cz> Cc: Franck Bui-Huu <vagabon.xyz@gmail.com> Cc: Nigel Cunningham <nigel@nigel.suspend2.net> Signed-off-by: Len Brown <len.brown@intel.com>
2007-10-18PM: Move definition of struct pm_ops to suspend.hRafael J. Wysocki
Move the definition of 'struct pm_ops' and related functions from <linux/pm.h> to <linux/suspend.h> . There are, at least, the following reasons to do that: * 'struct pm_ops' is specifically related to suspend and not to the power management in general. * As long as 'struct pm_ops' is defined in <linux/pm.h>, any modification of it causes the entire kernel to be recompiled, which is unnecessary and annoying. * Some suspend-related features are already defined in <linux/suspend.h>, so it is logical to move the definition of 'struct pm_ops' into there. * 'struct hibernation_ops', being the hibernation-related counterpart of 'struct pm_ops', is defined in <linux/suspend.h> . Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Pavel Machek <pavel@ucw.cz> Cc: Len Brown <lenb@kernel.org> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17Freezer: make kernel threads nonfreezable by defaultRafael J. Wysocki
Currently, the freezer treats all tasks as freezable, except for the kernel threads that explicitly set the PF_NOFREEZE flag for themselves. This approach is problematic, since it requires every kernel thread to either set PF_NOFREEZE explicitly, or call try_to_freeze(), even if it doesn't care for the freezing of tasks at all. It seems better to only require the kernel threads that want to or need to be frozen to use some freezer-related code and to remove any freezer-related code from the other (nonfreezable) kernel threads, which is done in this patch. The patch causes all kernel threads to be nonfreezable by default (ie. to have PF_NOFREEZE set by default) and introduces the set_freezable() function that should be called by the freezable kernel threads in order to unset PF_NOFREEZE. It also makes all of the currently freezable kernel threads call set_freezable(), so it shouldn't cause any (intentional) change of behaviour to appear. Additionally, it updates documentation to describe the freezing of tasks more accurately. [akpm@linux-foundation.org: build fixes] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Nigel Cunningham <nigel@nigel.suspend2.net> Cc: Pavel Machek <pavel@ucw.cz> Cc: Oleg Nesterov <oleg@tv-sign.ru> Cc: Gautham R Shenoy <ego@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-09[APM] Add shared version of APM emulationRalf Baechle
Currently ARM and MIPS both have nearly identical copies of the APM emulation code in their arch code. Add yet another copy of it to drivers char and make it selectable through SYS_SUPPORTS_APM_EMULATION. Signed-off-by: Ralf Baechle <ralf@linux-mips.org>