Commit Graph

1084 Commits

Author SHA1 Message Date
Rafael J. Wysocki
3c07cbc488 PM / Domains: Do not take parent locks to modify subdomain counters
After the subdomain counter in struct generic_pm_domain has been
changed into an atomic_t field, it is possible to modify
pm_genpd_poweron() and pm_genpd_poweroff() so that they don't take
the parents locks.  This requires pm_genpd_poweron() to increment
the parent's subdomain counter before calling itself recursively
for the parent and to decrement it if an error is to be returned.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25 15:33:43 +02:00
Rafael J. Wysocki
c4bb3160c8 PM / Domains: Implement subdomain counters as atomic fields
Currently, pm_genpd_poweron() and pm_genpd_poweroff() need to take
the parent PM domain's lock in order to modify the parent's counter
of active subdomains in a nonracy way.  This causes the locking to be
considerably complex and in fact is not necessary, because the
subdomain counters may be implemented as atomic fields and they
won't have to be modified under a lock.

Replace the unsigned in sd_count field in struct generic_pm_domain
by an atomic_t one and modify the code in drivers/base/power/domain.c
to take this change into account.

This patch doesn't change the locking yet, that is going to be done
in a separate subsequent patch.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-25 15:33:43 +02:00
Rafael J. Wysocki
b7ab83edba PM: Use spinlock instead of mutex in clock management functions
The lock member of struct pm_clk_data is of type struct mutex,
which is a problem, because the suspend and resume routines
defined in drivers/base/power/clock_ops.c cannot be executed
with interrupts disabled for this reason.  Modify
struct pm_clk_data so that its lock member is a spinlock.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
2011-08-24 21:40:56 +02:00
Linus Torvalds
b4fd4ae6c6 Merge branch 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
* 'pm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / Domains: Fix build for CONFIG_PM_RUNTIME unset
2011-08-17 13:15:25 -07:00
Stephen Rothwell
b5ddbf465f regmap: using module facilities requires module.h
Commit b33f9cbd67 ("regmap: Specify a module license") added a
MODULES_LICENSE to this file without adding an include of module.h.

module.h should have been included anyway, since this file has
EXPORT_SYMBOLs as well.  With the pending module.h split up, this would
probably have caused build problems.

Cc: Stephen Warren <swarren@nvidia.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-15 19:28:17 -07:00
Linus Torvalds
259a53407d Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: Specify a module license
  regmap: Fix bulk reads
2011-08-15 08:35:54 -07:00
Rafael J. Wysocki
17f2ae7f67 PM / Domains: Fix build for CONFIG_PM_RUNTIME unset
Function genpd_queue_power_off_work() is not defined for
CONFIG_PM_RUNTIME, so pm_genpd_poweroff_unused() causes a build
error to happen in that case.  Fix the problem by making
pm_genpd_poweroff_unused() depend on CONFIG_PM_RUNTIME too.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-14 13:34:31 +02:00
Stephen Warren
b33f9cbd67 regmap: Specify a module license
CONFIG_REGMAP_I2C/SPI are set to m when selected by a tristate config
option that's set to m. The regmap modules don't specify a license, so
fail to link to regmap_init at load time, since that is EXPORT_SYMBOL_GPL.
Fix this by specifying a license for the regmap modules.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-08-12 10:42:02 +09:00
Kevin Hilman
02b26774af PM / Runtime: Allow _put_sync() from interrupts-disabled context
Currently the use of pm_runtime_put_sync() is not safe from
interrupts-disabled context because rpm_idle() will release the
spinlock and enable interrupts for the idle callbacks.  This enables
interrupts during a time where interrupts were expected to be
disabled, and can have strange side effects on drivers that expected
interrupts to be disabled.

This is not a bug since the documentation clearly states that only
_put_sync_suspend() is safe in IRQ-safe mode.

However, pm_runtime_put_sync() could be made safe when in IRQ-safe
mode by releasing the spinlock but not re-enabling interrupts, which
is what this patch aims to do.

Problem was found when using some buggy drivers that set
pm_runtime_irq_safe() and used _put_sync() in interrupts-disabled
context.

Reported-by: Colin Cross <ccross@google.com>
Tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-05 21:45:20 +02:00
Rafael J. Wysocki
fe202fde50 PM / Domains: Fix pm_genpd_poweron()
The local variable ret is defined twice in pm_genpd_poweron(), which
causes this function to always return 0, even if the PM domain's
.power_on() callback fails, in which case an error code should be
returned.

Remove the wrong second definition of ret and additionally remove an
unnecessary definition of wait from pm_genpd_poweron().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-08-05 21:45:11 +02:00
Al Viro
9d108d2548 devtmpfs: missing initialialization in never-hit case
create_path() on something without a single / in it will return err
without initializing it.  It actually can't happen (we call that thing
only if create on the same path returns -ENOENT, which won't happen
happen for single-component path), but in this case initializing err
to 0 is more than making compiler to STFU - would be the right thing
to return on such paths; the function creates a parent directory of
given pathname and in that case it has no work to do...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-27 22:27:33 -04:00
Arun Sharma
60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@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>
2011-07-26 16:49:47 -07:00
Jonghwan Choi
fc92805a8e drivers/base/power/opp.c: fix dev_opp initial value
Dev_opp initial value shoule be ERR_PTR(), IS_ERR() is used to check
error.

Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:41 -07:00
Linus Torvalds
f0deb97ab1 Merge branch 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6
* 'driver-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6:
  updated Documentation/ja_JP/SubmittingPatches
  debugfs: add documentation for debugfs_create_x64
  uio: uio_pdrv_genirq: Add OF support
  firmware: gsmi: remove sysfs entries when unload the module
  Documentation/zh_CN: Fix messy code file email-clients.txt
  driver core: add more help description for "path to uevent helper"
  driver-core: modify FIRMWARE_IN_KERNEL help message
  driver-core: Kconfig grammar corrections in firmware configuration
  DOCUMENTATION: Replace create_device() with device_create().
  DOCUMENTATION: Update overview.txt in Doc/driver-model.
  pti: pti_tty_install documentation mispelling.
2011-07-25 23:06:24 -07:00
Linus Torvalds
184475029a Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (99 commits)
  drivers/virt: add missing linux/interrupt.h to fsl_hypervisor.c
  powerpc/85xx: fix mpic configuration in CAMP mode
  powerpc: Copy back TIF flags on return from softirq stack
  powerpc/64: Make server perfmon only built on ppc64 server devices
  powerpc/pseries: Fix hvc_vio.c build due to recent changes
  powerpc: Exporting boot_cpuid_phys
  powerpc: Add CFAR to oops output
  hvc_console: Add kdb support
  powerpc/pseries: Fix hvterm_raw_get_chars to accept < 16 chars, fixing xmon
  powerpc/irq: Quieten irq mapping printks
  powerpc: Enable lockup and hung task detectors in pseries and ppc64 defeconfigs
  powerpc: Add mpt2sas driver to pseries and ppc64 defconfig
  powerpc: Disable IRQs off tracer in ppc64 defconfig
  powerpc: Sync pseries and ppc64 defconfigs
  powerpc/pseries/hvconsole: Fix dropped console output
  hvc_console: Improve tty/console put_chars handling
  powerpc/kdump: Fix timeout in crash_kexec_wait_realmode
  powerpc/mm: Fix output of total_ram.
  powerpc/cpufreq: Add cpufreq driver for Momentum Maple boards
  powerpc: Correct annotations of pmu registration functions
  ...

Fix up trivial Kconfig/Makefile conflicts in arch/powerpc, drivers, and
drivers/cpufreq
2011-07-25 22:59:39 -07:00
Linus Torvalds
0003230e82 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  fs: take the ACL checks to common code
  bury posix_acl_..._masq() variants
  kill boilerplates around posix_acl_create_masq()
  generic_acl: no need to clone acl just to push it to set_cached_acl()
  kill boilerplate around posix_acl_chmod_masq()
  reiserfs: cache negative ACLs for v1 stat format
  xfs: cache negative ACLs if there is no attribute fork
  9p: do no return 0 from ->check_acl without actually checking
  vfs: move ACL cache lookup into generic code
  CIFS: Fix oops while mounting with prefixpath
  xfs: Fix wrong return value of xfs_file_aio_write
  fix devtmpfs race
  caam: don't pass bogus S_IFCHR to debugfs_create_...()
  get rid of create_proc_entry() abuses - proc_mkdir() is there for purpose
  asus-wmi: ->is_visible() can't return negative
  fix jffs2 ACLs on big-endian with 16bit mode_t
  9p: close ACL leaks
  ocfs2_init_acl(): fix a leak
  VFS : mount lock scalability for internal mounts
2011-07-25 12:53:15 -07:00
Al Viro
e13889bab3 fix devtmpfs race
After we's done complete(&req->done), there's nothing to prevent the
scope containing *req from being gone and *req overwritten by any
kind of junk.  So we must read req->next before that...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-25 14:15:50 -04:00
Mark Brown
40c5cc2639 regmap: Fix bulk reads
We should be reading the number of bytes we were asked for, not the size
of a single register.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-07-24 22:44:51 +01:00
Linus Torvalds
f5fc87905e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regulator: Convert tps65023 to use regmap API
  regmap: Add SPI bus support
  regmap: Add I2C bus support
  regmap: Add generic non-memory mapped register access API
2011-07-23 11:14:47 -07:00
Mark Brown
a676f08306 regmap: Add SPI bus support
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-07-23 07:56:59 +01:00
Mark Brown
9943fa300a regmap: Add I2C bus support
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-07-23 07:56:39 +01:00
Mark Brown
b83a313bf2 regmap: Add generic non-memory mapped register access API
There are many places in the tree where we implement register access for
devices on non-memory mapped buses, especially I2C and SPI. Since hardware
designers seem to have settled on a relatively consistent set of register
interfaces this can be effectively factored out into shared code.  There
are a standard set of formats for marshalling data for exchange with the
device, with the actual I/O mechanisms generally being simple byte
streams.

We create an abstraction for marshaling data into formats which can be
sent on the control interfaces, and create a standard method for
plugging in actual transport underneath that.

This is mostly a refactoring and renaming of the bottom level of the
existing code for sharing register I/O which we have in ASoC. A
subsequent patch in this series converts ASoC to use this.  The main
difference in interface is that reads return values by writing to a
location provided by a pointer rather than in the return value, ensuring
we can use the full range of the type for register data.  We also use
unsigned types rather than ints for the same reason.

As some of the devices can have very large register maps the existing
ASoC code also contains infrastructure for managing register caches.
This cache work will be moved over in a future stage to allow for
separate review, the current patch only deals with the physical I/O.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-07-23 07:56:03 +01:00
Linus Torvalds
bbd9d6f7fb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (107 commits)
  vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp
  isofs: Remove global fs lock
  jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory
  fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.
  mm/truncate.c: fix build for CONFIG_BLOCK not enabled
  fs:update the NOTE of the file_operations structure
  Remove dead code in dget_parent()
  AFS: Fix silly characters in a comment
  switch d_add_ci() to d_splice_alias() in "found negative" case as well
  simplify gfs2_lookup()
  jfs_lookup(): don't bother with . or ..
  get rid of useless dget_parent() in btrfs rename() and link()
  get rid of useless dget_parent() in fs/btrfs/ioctl.c
  fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
  drivers: fix up various ->llseek() implementations
  fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
  Ext4: handle SEEK_HOLE/SEEK_DATA generically
  Btrfs: implement our own ->llseek
  fs: add SEEK_HOLE and SEEK_DATA flags
  reiserfs: make reiserfs default to barrier=flush
  ...

Fix up trivial conflicts in fs/xfs/linux-2.6/xfs_super.c due to the new
shrinker callout for the inode cache, that clashed with the xfs code to
start the periodic workers later.
2011-07-22 19:02:39 -07:00
Linus Torvalds
6d16d6d9bb Merge branch 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-iommu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  iommu/core: Fix build with INTR_REMAP=y && CONFIG_DMAR=n
  iommu/amd: Don't use MSI address range for DMA addresses
  iommu/amd: Move missing parts to drivers/iommu
  iommu: Move iommu Kconfig entries to submenu
  x86/ia64: intel-iommu: move to drivers/iommu/
  x86: amd_iommu: move to drivers/iommu/
  msm: iommu: move to drivers/iommu/
  drivers: iommu: move to a dedicated folder
  x86/amd-iommu: Store device alias as dev_data pointer
  x86/amd-iommu: Search for existind dev_data before allocting a new one
  x86/amd-iommu: Allow dev_data->alias to be NULL
  x86/amd-iommu: Use only dev_data in low-level domain attach/detach functions
  x86/amd-iommu: Use only dev_data for dte and iotlb flushing routines
  x86/amd-iommu: Store ATS state in dev_data
  x86/amd-iommu: Store devid in dev_data
  x86/amd-iommu: Introduce global dev_data_list
  x86/amd-iommu: Remove redundant device_flush_dte() calls
  iommu-api: Add missing header file

Fix up trivial conflicts (independent additions close to each other) in
drivers/Makefile and include/linux/pci.h
2011-07-22 16:39:42 -07:00
Al Viro
5da4e68944 devtmpfs: get rid of bogus mkdir in create_path()
We do _NOT_ want to mkdir the path itself - we are preparing to
mknod it, after all.  Normally it'll fail with -ENOENT and
just do nothing, but if somebody has created the parent in
the meanwhile, we'll get buggered...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:11 -04:00
Al Viro
69753a0f14 switch devtmpfs to kern_path_create()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:10 -04:00
Al Viro
2780f1ff6a switch devtmpfs object creation/removal to separate kernel thread
... and give it a namespace where devtmpfs would be mounted on root,
thus avoiding abuses of vfs_path_lookup() (it was never intended to
be used with LOOKUP_PARENT).  Games with credentials are also gone.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:44:09 -04:00
Rafael J. Wysocki
7ae033cc0d Merge branch 'pm-runtime' into for-linus
* pm-runtime:
  OMAP: PM: disable idle on suspend for GPIO and UART
  OMAP: PM: omap_device: add API to disable idle on suspend
  OMAP: PM: omap_device: add system PM methods for PM domain handling
  OMAP: PM: omap_device: conditionally use PM domain runtime helpers
  PM / Runtime: Add new helper function: pm_runtime_status_suspended()
  PM / Runtime: Consistent utilization of deferred_resume
  PM / Runtime: Prevent runtime_resume from racing with probe
  PM / Runtime: Replace "run-time" with "runtime" in documentation
  PM / Runtime: Improve documentation of enable, disable and barrier
  PM: Limit race conditions between runtime PM and system sleep (v2)
  PCI / PM: Detect early wakeup in pci_pm_prepare()
  PM / Runtime: Return special error code if runtime PM is disabled
  PM / Runtime: Update documentation of interactions with system sleep
2011-07-15 23:59:25 +02:00
Rafael J. Wysocki
ba1389d74f Merge branch 'pm-domains' into for-linus
* pm-domains: (33 commits)
  ARM / shmobile: Return -EBUSY from A4LC power off if A3RV is active
  PM / Domains: Take .power_off() error code into account
  ARM / shmobile: Use genpd_queue_power_off_work()
  ARM / shmobile: Use pm_genpd_poweroff_unused()
  PM / Domains: Introduce function to power off all unused PM domains
  PM / Domains: Queue up power off work only if it is not pending
  PM / Domains: Improve handling of wakeup devices during system suspend
  PM / Domains: Do not restore all devices on power off error
  PM / Domains: Allow callbacks to execute all runtime PM helpers
  PM / Domains: Do not execute device callbacks under locks
  PM / Domains: Make failing pm_genpd_prepare() clean up properly
  PM / Domains: Set device state to "active" during system resume
  ARM: mach-shmobile: sh7372 A3RV requires A4LC
  PM / Domains: Export pm_genpd_poweron() in header
  ARM: mach-shmobile: sh7372 late pm domain off
  ARM: mach-shmobile: Runtime PM late init callback
  ARM: mach-shmobile: sh7372 D4 support
  ARM: mach-shmobile: sh7372 A4MP support
  ARM: mach-shmobile: sh7372: make sure that fsi is peripheral of spu2
  ARM: mach-shmobile: sh7372 A3SG support
  ...
2011-07-15 23:59:09 +02:00
Rafael J. Wysocki
1d8047a6f7 PM: Add "RTC" to PM trace time stamps to avoid confusion
Some users are apparently confused by dmesg output from
read_magic_time(), which looks like "real" time and date.
Add the "RTC" string to time stamps printed by read_magic_time() to
avoid that confusion.

Reported-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-15 23:58:19 +02:00
Nishanth Menon
99f381d354 PM / OPP: Introduce function to free cpufreq table
cpufreq table allocated by opp_init_cpufreq_table is better
freed by OPP layer itself. This allows future modifications to
the table handling to be transparent to the users.

Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-15 23:58:18 +02:00
Rafael J. Wysocki
d28054020f PM / Domains: Take .power_off() error code into account
Currently pm_genpd_poweroff() discards error codes returned by
the PM domain's .power_off() callback, because it's safer to always
regard the domain as inaccessible to drivers after a failing
.power_off().  Still, there are situations in which the low-level
code may want to indicate that it doesn't want to power off the
domain, so allow it to do that by returning -EBUSY from .power_off().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
2011-07-14 20:59:20 +02:00
Rafael J. Wysocki
0bc5b2debb ARM / shmobile: Use genpd_queue_power_off_work()
Make pd_power_down_a3rv() use genpd_queue_power_off_work() to queue
up the powering off of the A4LC domain to avoid queuing it up when
it is pending.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
2011-07-14 20:59:07 +02:00
Rafael J. Wysocki
5125bbf388 PM / Domains: Introduce function to power off all unused PM domains
Add a new function pm_genpd_poweroff_unused() queuing up the
execution of pm_genpd_poweroff() for every initialized generic PM
domain.  Calling it will cause every generic PM domain without
devices in use to be powered off.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>
2011-07-13 12:31:52 +02:00
Benjamin Herrenschmidt
a63fdc5156 mm: Move definition of MIN_MEMORY_BLOCK_SIZE to a header
The macro MIN_MEMORY_BLOCK_SIZE is currently defined twice in two .c
files, and I need it in a third one to fix a powerpc bug, so let's
first move it into a header

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
2011-07-12 11:08:01 +10:00
Rafael J. Wysocki
56375fd420 PM / Domains: Queue up power off work only if it is not pending
In theory it is possible that pm_genpd_poweroff() for two different
subdomains of the same parent domain will attempt to queue up the
execution of pm_genpd_poweroff() for the parent twice in a row.  This
would lead to unpleasant consequences, so prevent it from happening
by checking if genpd->power_off_work is pending before attempting to
queue it up.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-12 00:40:03 +02:00
Rafael J. Wysocki
4ecd6e651d PM / Domains: Improve handling of wakeup devices during system suspend
Kevin points out that if there's a device that can wake up the system
from sleep states, but it doesn't generate wakeup signals by itself
(they are generated on its behalf by other parts of the system) and
it currently is not enabled to wake up the system (that is,
device_may_wakeup() returns "false" for it), we may need to change
its wakeup settings during system suspend (for example, the device
might have been configured to signal remote wakeup from the system's
working state, as needed by runtime PM).  Therefore the generic PM
domains code should invoke the system suspend callbacks provided by
the device's driver, which it doesn't do if the PM domain is powered
off during the system suspend's "prepare" stage.  This is a valid
point.  Moreover, this code also should make sure that system wakeup
devices that are enabled to wake up the system from sleep states and
have to remain active for this purpose are not suspended while the
system is in a sleep state.

To avoid the above issues, make the generic PM domains' .prepare()
routine, pm_genpd_prepare(), force runtime resume of devices whose
system wakeup settings may need to be changed during system suspend
or that should remain active while the system is in a sleep state to
be able to wake it up from that state.

Reported-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-12 00:39:57 +02:00
Rafael J. Wysocki
697a7f3727 PM / Domains: Do not restore all devices on power off error
Since every device in a PM domain has its own need_restore
flag, which is set by __pm_genpd_save_device(), there's no need to
walk the domain's device list and restore all devices on an error
from one of the drivers' .runtime_suspend() callbacks.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-12 00:39:48 +02:00
Rafael J. Wysocki
c6d22b3726 PM / Domains: Allow callbacks to execute all runtime PM helpers
A deadlock may occur if one of the PM domains' .start_device() or
.stop_device() callbacks or a device driver's .runtime_suspend() or
.runtime_resume() callback executed by the core generic PM domain
code uses a "wrong" runtime PM helper function.  This happens, for
example, if .runtime_resume() from one device's driver calls
pm_runtime_resume() for another device in the same PM domain.
A similar situation may take place if a device's parent is in the
same PM domain, in which case the runtime PM framework may execute
pm_genpd_runtime_resume() automatically for the parent (if it is
suspended at the moment).  This, of course, is undesirable, so
the generic PM domains code should be modified to prevent it from
happening.

The runtime PM framework guarantees that pm_genpd_runtime_suspend()
and pm_genpd_runtime_resume() won't be executed in parallel for
the same device, so the generic PM domains code need not worry
about those cases.  Still, it needs to prevent the other possible
race conditions between pm_genpd_runtime_suspend(),
pm_genpd_runtime_resume(), pm_genpd_poweron() and pm_genpd_poweroff()
from happening and it needs to avoid deadlocks at the same time.
To this end, modify the generic PM domains code to relax
synchronization rules so that:

* pm_genpd_poweron() doesn't wait for the PM domain status to
  change from GPD_STATE_BUSY.  If it finds that the status is
  not GPD_STATE_POWER_OFF, it returns without powering the domain on
  (it may modify the status depending on the circumstances).

* pm_genpd_poweroff() returns as soon as it finds that the PM
  domain's status changed from GPD_STATE_BUSY after it's released
  the PM domain's lock.

* pm_genpd_runtime_suspend() doesn't wait for the PM domain status
  to change from GPD_STATE_BUSY after executing the domain's
  .stop_device() callback and executes pm_genpd_poweroff() only
  if pm_genpd_runtime_resume() is not executed in parallel.

* pm_genpd_runtime_resume() doesn't wait for the PM domain status
  to change from GPD_STATE_BUSY after executing pm_genpd_poweron()
  and sets the domain's status to GPD_STATE_BUSY and increments its
  counter of resuming devices (introduced by this change) immediately
  after acquiring the lock.  The counter of resuming devices is then
  decremented after executing __pm_genpd_runtime_resume() for the
  device and the domain's status is reset to GPD_STATE_ACTIVE (unless
  there are more resuming devices in the domain, in which case the
  status remains GPD_STATE_BUSY).

This way, for example, if a device driver's .runtime_resume()
callback executes pm_runtime_resume() for another device in the same
PM domain, pm_genpd_poweron() called by pm_genpd_runtime_resume()
invoked by the runtime PM framework will not block and it will see
that there's nothing to do for it.  Next, the PM domain's lock will
be acquired without waiting for its status to change from
GPD_STATE_BUSY and the device driver's .runtime_resume() callback
will be executed.  In turn, if pm_runtime_suspend() is executed by
one device driver's .runtime_resume() callback for another device in
the same PM domain, pm_genpd_poweroff() executed by
pm_genpd_runtime_suspend() invoked by the runtime PM framework as a
result will notice that one of the devices in the domain is being
resumed, so it will return immediately.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-12 00:39:36 +02:00
Rafael J. Wysocki
17b75eca76 PM / Domains: Do not execute device callbacks under locks
Currently, the .start_device() and .stop_device() callbacks from
struct generic_pm_domain() as well as the device drivers' runtime PM
callbacks used by the generic PM domains code are executed under
the generic PM domain lock.  This, unfortunately, is prone to
deadlocks, for example if a device and its parent are boths members
of the same PM domain.  For this reason, it would be better if the
PM domains code didn't execute device callbacks under the lock.

Rework the locking in the generic PM domains code so that the lock
is dropped for the execution of device callbacks.  To this end,
introduce PM domains states reflecting the current status of a PM
domain and such that the PM domain lock cannot be acquired if the
status is GPD_STATE_BUSY.  Make threads attempting to acquire a PM
domain's lock wait until the status changes to either
GPD_STATE_ACTIVE or GPD_STATE_POWER_OFF.

This change by itself doesn't fix the deadlock problem mentioned
above, but the mechanism introduced by it will be used for for this
purpose by a subsequent patch.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-12 00:39:29 +02:00
Rafael J. Wysocki
b6c10c8466 PM / Domains: Make failing pm_genpd_prepare() clean up properly
If pm_generic_prepare() in pm_genpd_prepare() returns error code,
the PM domains counter of "prepared" devices should be decremented
and its suspend_power_off flag should be reset if this counter drops
down to zero.  Otherwise, the PM domain runtime PM code will not
handle the domain correctly (it will permanently think that system
suspend is in progress).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-12 00:39:21 +02:00
Rafael J. Wysocki
6f00ff7827 PM / Domains: Set device state to "active" during system resume
The runtime PM status of devices in a power domain that is not
powered off in pm_genpd_complete() should be set to "active", because
those devices are operational at this point.  Some of them may not be
in use, though, so make pm_genpd_complete() call pm_runtime_idle()
in addition to pm_runtime_set_active() for each of them.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-12 00:39:10 +02:00
Colin Cross
887596224c PM: Reintroduce dropped call to check_wakeup_irqs
Patch 2e711c04db
(PM: Remove sysdev suspend, resume and shutdown operations)
deleted sysdev_suspend(), which was being relied on to call
check_wakeup_irqs() in suspend.  If check_wakeup_irqs() is not
called, wake interrupts that are pending when suspend is
entered may be lost.  It also breaks IRQCHIP_MASK_ON_SUSPEND,
which is handled in check_wakeup_irqs().

This patch adds a call to check_wakeup_irqs() in syscore_suspend(),
similar to what was deleted in sysdev_suspend().

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-11 10:51:49 +02:00
Magnus Damm
18b4f3f5d0 PM / Domains: Export pm_genpd_poweron() in header
Allow SoC-specific code to call pm_genpd_poweron().

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-10 10:39:14 +02:00
ShuoX Liu
2cffff1281 PM / Runtime: Consistent utilization of deferred_resume
dev->power.deferred_resume is used as a bool typically, so change
one assignment to false from 0, like other places.

Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
2011-07-08 20:53:55 +02:00
Kumar Gala
a77ce8167c driver core: Add ability for arch code to setup pdev_archdata
On some architectures we need to setup pdev_archdata before we add the
device.  Waiting til a bus_notifier is too late since we might need the
pdev_archdata in the bus notifier.  One example is setting up of dma_mask
pointers such that it can be used in a bus_notifier.

We add weak noop version of arch_setup_pdev_archdata() and allow the arch
code to override with access the full definitions of struct device,
struct platform_device, and struct pdev_archdata.

Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
2011-07-08 00:21:35 -05:00
Ingo Molnar
b395fb36d5 Merge branch 'iommu-3.1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu into core/iommu 2011-07-07 12:58:28 +02:00
Alan Stern
69c843b45e PM / Runtime: Prevent runtime_resume from racing with probe
This patch (as1475) adds device_lock() and device_unlock() calls to
the store methods for the power/control and power/autosuspend_delay_ms
sysfs attribute files.  We don't want badly timed writes to these
files to cause runtime_resume callbacks to occur while a driver is
being probed for a device.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-06 10:52:23 +02:00
Rafael J. Wysocki
62052ab1d1 PM / Runtime: Replace "run-time" with "runtime" in documentation
The runtime PM documentation and kerneldoc comments sometimes spell
"runtime" with a dash (i.e. "run-time").  Replace all of those
instances with "runtime" to make the naming consistent.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-07-06 10:52:13 +02:00
Rafael J. Wysocki
1e2ef05bb8 PM: Limit race conditions between runtime PM and system sleep (v2)
One of the roles of the PM core is to prevent different PM callbacks
executed for the same device object from racing with each other.
Unfortunately, after commit e866500247
(PM: Allow pm_runtime_suspend() to succeed during system suspend)
runtime PM callbacks may be executed concurrently with system
suspend/resume callbacks for the same device.

The main reason for commit e866500247
was that some subsystems and device drivers wanted to use runtime PM
helpers, pm_runtime_suspend() and pm_runtime_put_sync() in
particular, for carrying out the suspend of devices in their
.suspend() callbacks.  However, as it's been determined recently,
there are multiple reasons not to do so, inlcuding:

 * The caller really doesn't control the runtime PM usage counters,
   because user space can access them through sysfs and effectively
   block runtime PM.  That means using pm_runtime_suspend() or
   pm_runtime_get_sync() to suspend devices during system suspend
   may or may not work.

 * If a driver calls pm_runtime_suspend() from its .suspend()
   callback, it causes the subsystem's .runtime_suspend() callback to
   be executed, which leads to the call sequence:

   subsys->suspend(dev)
      driver->suspend(dev)
         pm_runtime_suspend(dev)
            subsys->runtime_suspend(dev)

   recursive from the subsystem's point of view.  For some subsystems
   that may actually work (e.g. the platform bus type), but for some
   it will fail in a rather spectacular fashion (e.g. PCI).  In each
   case it means a layering violation.

 * Both the subsystem and the driver can provide .suspend_noirq()
   callbacks for system suspend that can do whatever the
   .runtime_suspend() callbacks do just fine, so it really isn't
   necessary to call pm_runtime_suspend() during system suspend.

 * The runtime PM's handling of wakeup devices is usually different
   from the system suspend's one, so .runtime_suspend() may simply be
   inappropriate for system suspend.

 * System suspend is supposed to work even if CONFIG_PM_RUNTIME is
   unset.

 * The runtime PM workqueue is frozen before system suspend, so if
   whatever the driver is going to do during system suspend depends
   on it, that simply won't work.

Still, there is a good reason to allow pm_runtime_resume() to
succeed during system suspend and resume (for instance, some
subsystems and device drivers may legitimately use it to ensure that
their devices are in full-power states before suspending them).
Moreover, there is no reason to prevent runtime PM callbacks from
being executed in parallel with the system suspend/resume .prepare()
and .complete() callbacks and the code removed by commit
e866500247 went too far in this
respect.  On the other hand, runtime PM callbacks, including
.runtime_resume(), must not be executed during system suspend's
"late" stage of suspending devices and during system resume's "early"
device resume stage.

Taking all of the above into consideration, make the PM core
acquire a runtime PM reference to every device and resume it if
there's a runtime PM resume request pending right before executing
the subsystem-level .suspend() callback for it.  Make the PM core
drop references to all devices right after executing the
subsystem-level .resume() callbacks for them.  Additionally,
make the PM core disable the runtime PM framework for all devices
during system suspend, after executing the subsystem-level .suspend()
callbacks for them, and enable the runtime PM framework for all
devices during system resume, right before executing the
subsystem-level .resume() callbacks for them.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Kevin Hilman <khilman@ti.com>
2011-07-06 10:51:58 +02:00