Fix dev_pm_put_subsys_data() so that it doesn't call kfree() under
a spinlock and make it return 1 whenever it leaves NULL
power.subsys_data (regardless of the reason).
Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Reviewed-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-assorted:
PM / OPP: add documentation to RCU head in struct opp
PM / sleep: invalidate TEST_CPUS and TEST_CORE support for freeze state
PM / sleep: add TEST_PLATFORM support for freeze state
When genpd prepares for a system suspend it will fetch a runtime
reference for the device. When returning it we now use the
asyncronous runtime PM API. Thus we don't have to wait for the
device to become idle|suspended before we move on and handle the
next device in queue.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
For irq safe devices return the runtime reference for the parent
by using the asyncronous runtime PM API. Thus we don't have to
wait for it to become idle|suspended. Instead we can move on and
handle the next device in queue.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Use the asyncronous runtime PM API when returning the runtime
reference for the device after the system resume is completed.
By using the asyncronous runtime PM API we don't have to wait
for each an every device to become idle|suspended. Instead we
can move on and handle the next device in queue.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
commit dde8437 (PM / OPP: RCU reclaim) introduced rcu_head for
struct opp. This aids freeing using kfree_rcu. However, we missed
adding documentation for the same. This generates kernel doc warning:
Warning(drivers/base/power/opp.c:70): No description found for
parameter 'head'
Add documentation as appropriate.
[rjw: Changelog]
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Commit b81ea1b (PM / QoS: Fix concurrency issues and memory leaks in
device PM QoS) put calls to pm_qos_sysfs_add_latency(),
pm_qos_sysfs_add_flags(), pm_qos_sysfs_remove_latency(), and
pm_qos_sysfs_remove_flags() under dev_pm_qos_mtx, which was a
mistake, because it may lead to deadlocks in some situations.
For example, if pm_qos_remote_wakeup_store() is run in parallel
with dev_pm_qos_constraints_destroy(), they may deadlock in the
following way:
======================================================
[ INFO: possible circular locking dependency detected ]
3.9.0-rc4-next-20130328-sasha-00014-g91a3267 #319 Tainted: G W
-------------------------------------------------------
trinity-child6/12371 is trying to acquire lock:
(s_active#54){++++.+}, at: [<ffffffff81301631>] sysfs_addrm_finish+0x31/0x60
but task is already holding lock:
(dev_pm_qos_mtx){+.+.+.}, at: [<ffffffff81f07cc3>] dev_pm_qos_constraints_destroy+0x23/0x250
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (dev_pm_qos_mtx){+.+.+.}:
[<ffffffff811811da>] lock_acquire+0x1aa/0x240
[<ffffffff83dab809>] __mutex_lock_common+0x59/0x5e0
[<ffffffff83dabebf>] mutex_lock_nested+0x3f/0x50
[<ffffffff81f07f2f>] dev_pm_qos_update_flags+0x3f/0xc0
[<ffffffff81f05f4f>] pm_qos_remote_wakeup_store+0x3f/0x70
[<ffffffff81efbb43>] dev_attr_store+0x13/0x20
[<ffffffff812ffdaa>] sysfs_write_file+0xfa/0x150
[<ffffffff8127f2c1>] __kernel_write+0x81/0x150
[<ffffffff812afc2d>] write_pipe_buf+0x4d/0x80
[<ffffffff812af57c>] splice_from_pipe_feed+0x7c/0x120
[<ffffffff812afa25>] __splice_from_pipe+0x45/0x80
[<ffffffff812b14fc>] splice_from_pipe+0x4c/0x70
[<ffffffff812b1538>] default_file_splice_write+0x18/0x30
[<ffffffff812afae3>] do_splice_from+0x83/0xb0
[<ffffffff812afb2e>] direct_splice_actor+0x1e/0x20
[<ffffffff812b0277>] splice_direct_to_actor+0xe7/0x200
[<ffffffff812b15bc>] do_splice_direct+0x4c/0x70
[<ffffffff8127eda9>] do_sendfile+0x169/0x300
[<ffffffff8127ff94>] SyS_sendfile64+0x64/0xb0
[<ffffffff83db7d18>] tracesys+0xe1/0xe6
-> #0 (s_active#54){++++.+}:
[<ffffffff811800cf>] __lock_acquire+0x15bf/0x1e50
[<ffffffff811811da>] lock_acquire+0x1aa/0x240
[<ffffffff81300aa2>] sysfs_deactivate+0x122/0x1a0
[<ffffffff81301631>] sysfs_addrm_finish+0x31/0x60
[<ffffffff812ff77f>] sysfs_hash_and_remove+0x7f/0xb0
[<ffffffff813035a1>] sysfs_unmerge_group+0x51/0x70
[<ffffffff81f068f4>] pm_qos_sysfs_remove_flags+0x14/0x20
[<ffffffff81f07490>] __dev_pm_qos_hide_flags+0x30/0x70
[<ffffffff81f07cd5>] dev_pm_qos_constraints_destroy+0x35/0x250
[<ffffffff81f06931>] dpm_sysfs_remove+0x11/0x50
[<ffffffff81efcf6f>] device_del+0x3f/0x1b0
[<ffffffff81efd128>] device_unregister+0x48/0x60
[<ffffffff82d4083c>] usb_hub_remove_port_device+0x1c/0x20
[<ffffffff82d2a9cd>] hub_disconnect+0xdd/0x160
[<ffffffff82d36ab7>] usb_unbind_interface+0x67/0x170
[<ffffffff81f001a7>] __device_release_driver+0x87/0xe0
[<ffffffff81f00559>] device_release_driver+0x29/0x40
[<ffffffff81effc58>] bus_remove_device+0x148/0x160
[<ffffffff81efd07f>] device_del+0x14f/0x1b0
[<ffffffff82d344f9>] usb_disable_device+0xf9/0x280
[<ffffffff82d34ff8>] usb_set_configuration+0x268/0x840
[<ffffffff82d3a7fc>] usb_remove_store+0x4c/0x80
[<ffffffff81efbb43>] dev_attr_store+0x13/0x20
[<ffffffff812ffdaa>] sysfs_write_file+0xfa/0x150
[<ffffffff8127f71d>] do_loop_readv_writev+0x4d/0x90
[<ffffffff8127f999>] do_readv_writev+0xf9/0x1e0
[<ffffffff8127faba>] vfs_writev+0x3a/0x60
[<ffffffff8127fc60>] SyS_writev+0x50/0xd0
[<ffffffff83db7d18>] tracesys+0xe1/0xe6
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(dev_pm_qos_mtx);
lock(s_active#54);
lock(dev_pm_qos_mtx);
lock(s_active#54);
*** DEADLOCK ***
To avoid that, remove the calls to functions mentioned above from
under dev_pm_qos_mtx and introduce a separate lock to prevent races
between functions that add or remove device PM QoS sysfs attributes
from happening.
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Device PM QoS sysfs attributes, if present during device removal,
are removed from within device_pm_remove(), which is too late,
since dpm_sysfs_remove() has already removed the whole attribute
group they belonged to. However, moving the removal of those
attributes to dpm_sysfs_remove() alone is not sufficient, because
in theory they still can be re-added right after being removed by it
(the device's driver is still bound to it at that point).
For this reason, move the entire desctruction of device PM QoS
constraints to dpm_sysfs_remove() and make it prevent any new
constraints from being added after it has run. Also, move the
initialization of the power.qos field in struct device to
device_pm_init_common() and drop the no longer needed
dev_pm_qos_constraints_init().
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The current device PM QoS code assumes that certain functions will
never be called in parallel with each other (for example, it is
assumed that dev_pm_qos_expose_flags() won't be called in parallel
with dev_pm_qos_hide_flags() for the same device and analogously
for the latency limit), which may be overly optimistic. Moreover,
dev_pm_qos_expose_flags() and dev_pm_qos_expose_latency_limit()
leak memory in error code paths (req needs to be freed on errors)
and __dev_pm_qos_drop_user_request() forgets to free the request.
To fix the above issues put more things under the device PM QoS
mutex to make them mutually exclusive and add the missing freeing
of memory.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull USB patches from Greg Kroah-Hartman:
"Here's the big USB merge for 3.9-rc1
Nothing major, lots of gadget fixes, and of course, xhci stuff.
All of this has been in linux-next for a while, with the exception of
the last 3 patches, which were reverts of patches in the tree that
caused problems, they went in yesterday."
* tag 'usb-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (190 commits)
Revert "USB: EHCI: make ehci-vt8500 a separate driver"
Revert "USB: EHCI: make ehci-orion a separate driver"
Revert "USB: update host controller Kconfig entries"
USB: update host controller Kconfig entries
USB: EHCI: make ehci-orion a separate driver
USB: EHCI: make ehci-vt8500 a separate driver
USB: usb-storage: unusual_devs update for Super TOP SATA bridge
USB: ehci-omap: Fix autoloading of module
USB: ehci-omap: Don't free gpios that we didn't request
USB: option: add Huawei "ACM" devices using protocol = vendor
USB: serial: fix null-pointer dereferences on disconnect
USB: option: add Yota / Megafon M100-1 4g modem
drivers/usb: add missing GENERIC_HARDIRQS dependencies
USB: storage: properly handle the endian issues of idProduct
testusb: remove all mentions of 'usbfs'
usb: gadget: imx_udc: make it depend on BROKEN
usb: omap_control_usb: fix compile warning
ARM: OMAP: USB: Add phy binding information
ARM: OMAP2: MUSB: Specify omap4 has mailbox
ARM: OMAP: devices: create device for usb part of control module
...
* pm-cpufreq: (55 commits)
cpufreq / intel_pstate: Fix 32 bit build
cpufreq: conservative: Fix typos in comments
cpufreq: ondemand: Fix typos in comments
cpufreq: exynos: simplify .init() for setting policy->cpus
cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs
cpufreq/x86: Add P-state driver for sandy bridge.
cpufreq_stats: do not remove sysfs files if frequency table is not present
cpufreq: Do not track governor name for scaling drivers with internal governors.
cpufreq: Only call cpufreq_out_of_sync() for driver that implement cpufreq_driver.target()
cpufreq: Retrieve current frequency from scaling drivers with internal governors
cpufreq: Fix locking issues
cpufreq: Create a macro for unlock_policy_rwsem{read,write}
cpufreq: Remove unused HOTPLUG_CPU code
cpufreq: governors: Fix WARN_ON() for multi-policy platforms
cpufreq: ondemand: Replace down_differential tuner with adj_up_threshold
cpufreq / stats: Get rid of CPUFREQ_STATDEVICE_ATTR
cpufreq: Don't check cpu_online(policy->cpu)
cpufreq: add imx6q-cpufreq driver
cpufreq: Don't remove sysfs link for policy->cpu
cpufreq: Remove unnecessary use of policy->shared_type
...
PM_SUSPEND_FREEZE state is a general state that
does not need any platform specific support, it equals
frozen processes + suspended devices + idle processors.
Compared with PM_SUSPEND_MEMORY,
PM_SUSPEND_FREEZE saves less power
because the system is still in a running state.
PM_SUSPEND_FREEZE has less resume latency because it does not
touch BIOS, and the processors are in idle state.
Compared with RTPM/idle,
PM_SUSPEND_FREEZE saves more power as
1. the processor has longer sleep time because processes are frozen.
The deeper c-state the processor supports, more power saving we can get.
2. PM_SUSPEND_FREEZE uses system suspend code path, thus we can get
more power saving from the devices that does not have good RTPM support.
This state is useful for
1) platforms that do not have STR, or have a broken STR.
2) platforms that have an extremely low power idle state,
which can be used to replace STR.
The following describes how PM_SUSPEND_FREEZE state works.
1. echo freeze > /sys/power/state
2. the processes are frozen.
3. all the devices are suspended.
4. all the processors are blocked by a wait queue
5. all the processors idles and enters (Deep) c-state.
6. an interrupt fires.
7. a processor is woken up and handles the irq.
8. if it is a general event,
a) the irq handler runs and quites.
b) goto step 4.
9. if it is a real wake event, say, power button pressing, keyboard touch, mouse moving,
a) the irq handler runs and activate the wakeup source
b) wakeup_source_activate() notifies the wait queue.
c) system starts resuming from PM_SUSPEND_FREEZE
10. all the devices are resumed.
11. all the processes are unfrozen.
12. system is back to working.
Known Issue:
The wakeup of this new PM_SUSPEND_FREEZE state may behave differently
from the previous suspend state.
Take ACPI platform for example, there are some GPEs that only enabled
when the system is in sleep state, to wake the system backk from S3/S4.
But we are not touching these GPEs during transition to PM_SUSPEND_FREEZE.
This means we may lose some wake event.
But on the other hand, as we do not disable all the Interrupts during
PM_SUSPEND_FREEZE, we may get some extra "wakeup" Interrupts, that are
not available for S3/S4.
The patches has been tested on an old Sony laptop, and here are the results:
Average Power:
1. RPTM/idle for half an hour:
14.8W, 12.6W, 14.1W, 12.5W, 14.4W, 13.2W, 12.9W
2. Freeze for half an hour:
11W, 10.4W, 9.4W, 11.3W 10.5W
3. RTPM/idle for three hours:
11.6W
4. Freeze for three hours:
10W
5. Suspend to Memory:
0.5~0.9W
Average Resume Latency:
1. RTPM/idle with a black screen: (From pressing keyboard to screen back)
Less than 0.2s
2. Freeze: (From pressing power button to screen back)
2.50s
3. Suspend to Memory: (From pressing power button to screen back)
4.33s
>From the results, we can see that all the platforms should benefit from
this patch, even if it does not have Low Power S0.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There's no need to test whether a (delayed) work item is pending
before queueing, flushing or cancelling it, so remove work_pending()
tests used in those cases.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Currently, the PM core disables runtime PM for all devices right
after executing subsystem/driver .suspend() callbacks for them
and re-enables it right before executing subsystem/driver .resume()
callbacks for them. This may lead to problems when there are
two devices such that the .suspend() callback executed for one of
them depends on runtime PM working for the other. In that case,
if runtime PM has already been disabled for the second device,
the first one's .suspend() won't work correctly (and analogously
for resume).
To make those issues go away, make the PM core disable runtime PM
for devices right before executing subsystem/driver .suspend_late()
callbacks for them and enable runtime PM for them right after
executing subsystem/driver .resume_early() callbacks for them. This
way the potential conflitcs between .suspend_late()/.resume_early()
and their runtime PM counterparts are still prevented from happening,
but the subtle ordering issues related to disabling/enabling runtime
PM for devices during system suspend/resume are much easier to avoid.
Reported-and-tested-by: Jan-Matthias Braun <jan_braun@gmx.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Kevin Hilman <khilman@deeprootsystems.com>
Cc: 3.4+ <stable@vger.kernel.org>
Local variable 'error' in dev_pm_qos_add_ancestor_request() need
not contain error codes only, so rename it to 'ret'.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* pm-qos:
PM / QoS: Handle device PM QoS flags while removing constraints
PM / QoS: Resume device before exposing/hiding PM QoS flags
PM / QoS: Document request manipulation requirement for flags
PM / QoS: Fix a free error in the dev_pm_qos_constraints_destroy()
PM / QoS: Fix the return value of dev_pm_qos_update_request()
PM / ACPI: Take device PM QoS flags into account
PM / Domains: Check device PM QoS flags in pm_genpd_poweroff()
PM / QoS: Make it possible to expose PM QoS device flags to user space
PM / QoS: Introduce PM QoS device flags support
PM / QoS: Prepare struct dev_pm_qos_request for more request types
PM / QoS: Introduce request and constraint data types for PM QoS flags
PM / QoS: Prepare device structure for adding more constraint types
PM QoS flags have to be handled by dev_pm_qos_constraints_destroy()
in the same way as PM QoS resume latency constraints. That is, if
they have been exposed to user space, they have to be hidden from it
and the list of flags requests has to be flushed before destroying
the device's PM QoS object. Make that happen.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
