208 Commits
Author SHA1 Message Date
Bart Van AsscheandRafael J. Wysocki 29ab768277 PM: runtime: Fix a race condition related to device removal
The following code in pm_runtime_work() may dereference the dev->parent
pointer after the parent device has been freed:

	/* Maybe the parent is now able to suspend. */
	if (parent && !parent->power.ignore_children) {
		spin_unlock(&dev->power.lock);

		spin_lock(&parent->power.lock);
		rpm_idle(parent, RPM_ASYNC);
		spin_unlock(&parent->power.lock);

		spin_lock(&dev->power.lock);
	}

Fix this by inserting a flush_work() call in pm_runtime_remove().

Without this patch blktest block/001 triggers the following complaint
sporadically:

BUG: KASAN: slab-use-after-free in lock_acquire+0x70/0x160
Read of size 1 at addr ffff88812bef7198 by task kworker/u553:1/3081
Workqueue: pm pm_runtime_work
Call Trace:
 <TASK>
 dump_stack_lvl+0x61/0x80
 print_address_description.constprop.0+0x8b/0x310
 print_report+0xfd/0x1d7
 kasan_report+0xd8/0x1d0
 __kasan_check_byte+0x42/0x60
 lock_acquire.part.0+0x38/0x230
 lock_acquire+0x70/0x160
 _raw_spin_lock+0x36/0x50
 rpm_suspend+0xc6a/0xfe0
 rpm_idle+0x578/0x770
 pm_runtime_work+0xee/0x120
 process_one_work+0xde3/0x1410
 worker_thread+0x5eb/0xfe0
 kthread+0x37b/0x480
 ret_from_fork+0x6cb/0x920
 ret_from_fork_asm+0x11/0x20
 </TASK>

Allocated by task 4314:
 kasan_save_stack+0x2a/0x50
 kasan_save_track+0x18/0x40
 kasan_save_alloc_info+0x3d/0x50
 __kasan_kmalloc+0xa0/0xb0
 __kmalloc_noprof+0x311/0x990
 scsi_alloc_target+0x122/0xb60 [scsi_mod]
 __scsi_scan_target+0x101/0x460 [scsi_mod]
 scsi_scan_channel+0x179/0x1c0 [scsi_mod]
 scsi_scan_host_selected+0x259/0x2d0 [scsi_mod]
 store_scan+0x2d2/0x390 [scsi_mod]
 dev_attr_store+0x43/0x80
 sysfs_kf_write+0xde/0x140
 kernfs_fop_write_iter+0x3ef/0x670
 vfs_write+0x506/0x1470
 ksys_write+0xfd/0x230
 __x64_sys_write+0x76/0xc0
 x64_sys_call+0x213/0x1810
 do_syscall_64+0xee/0xfc0
 entry_SYSCALL_64_after_hwframe+0x4b/0x53

Freed by task 4314:
 kasan_save_stack+0x2a/0x50
 kasan_save_track+0x18/0x40
 kasan_save_free_info+0x3f/0x50
 __kasan_slab_free+0x67/0x80
 kfree+0x225/0x6c0
 scsi_target_dev_release+0x3d/0x60 [scsi_mod]
 device_release+0xa3/0x220
 kobject_cleanup+0x105/0x3a0
 kobject_put+0x72/0xd0
 put_device+0x17/0x20
 scsi_device_dev_release+0xacf/0x12c0 [scsi_mod]
 device_release+0xa3/0x220
 kobject_cleanup+0x105/0x3a0
 kobject_put+0x72/0xd0
 put_device+0x17/0x20
 scsi_device_put+0x7f/0xc0 [scsi_mod]
 sdev_store_delete+0xa5/0x120 [scsi_mod]
 dev_attr_store+0x43/0x80
 sysfs_kf_write+0xde/0x140
 kernfs_fop_write_iter+0x3ef/0x670
 vfs_write+0x506/0x1470
 ksys_write+0xfd/0x230
 __x64_sys_write+0x76/0xc0
 x64_sys_call+0x213/0x1810

Reported-by: Ming Lei <ming.lei@redhat.com>
Closes: https://lore.kernel.org/all/ZxdNvLNI8QaOfD2d@fedora/
Reported-by: syzbot+6c905ab800f20cf4086c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/68c13942.050a0220.2ff435.000b.GAE@google.com/
Fixes: 5e928f77a0 ("PM: Introduce core framework for run-time PM of I/O devices (rev. 17)")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260312182720.2776083-1-bvanassche@acm.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2026-03-16 20:33:09 +01:00
Rafael J. Wysocki 359afc8eb0 PM: runtime: Do not clear needs_force_resume with enabled runtime PM
Commit 89d9cec3b1 ("PM: runtime: Clear power.needs_force_resume in
pm_runtime_reinit()") added provisional clearing of power.needs_force_resume
to pm_runtime_reinit(), but it is done unconditionally which is a
mistake because pm_runtime_reinit() may race with driver probing
and removal [1].

To address this, notice that power.needs_force_resume should never
be set when runtime PM is enabled and so it only needs to be cleared
when runtime PM is disabled, and update pm_runtime_init() to only
clear that flag when runtime PM is disabled.

Fixes: 89d9cec3b1 ("PM: runtime: Clear power.needs_force_resume in pm_runtime_reinit()")
Reported-by: Ed Tsai <ed.tsai@mediatek.com>
Closes: https://lore.kernel.org/linux-pm/20251215122154.3180001-1-ed.tsai@mediatek.com/ [1]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: 6.17+ <stable@vger.kernel.org> # 6.17+
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/12807571.O9o76ZdvQC@rafael.j.wysocki
2025-12-16 12:58:57 +01:00
Brian NorrisandRafael J. Wysocki 41f7351fc4 PM: runtime: Make pm_runtime_barrier() return void
No callers check the return code, and that's a good thing. Doing so
would be racy and unhelpful.

Drop the return code entirely, so we don't make anyone think about its
complexities.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://patch.msgid.link/20251202193129.1411419-2-briannorris@chromium.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-12-04 20:38:13 +01:00
Malaya Kumar RoutandRafael J. Wysocki 4e48e7baa3 PM: runtime: fix typos in runtime.c comments
Fix several typos in comments:
- "timesptamp" -> "timestamp"
- "involed" -> "involved"
- "nonero" -> "nonzero"

Fix typos in comments to improve code documentation clarity.

Signed-off-by: Malaya Kumar Rout <mrout@redhat.com>
Link: https://patch.msgid.link/20251026170527.262003-1-mrout@redhat.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-10-29 19:58:58 +01:00
Rafael J. Wysocki cea54f8e34 PM: runtime: docs: Update pm_runtime_allow/forbid() documentation
Drop confusing descriptions of pm_runtime_allow() and pm_runtime_forbid()
from Documentation/power/runtime_pm.rst and update the kerneldoc comments
of these functions to better explain their purpose.

Link: https://lore.kernel.org/linux-pm/08976178-298f-79d9-1d63-cff5a4e56cc3@linux.intel.com/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/12780841.O9o76ZdvQC@rafael.j.wysocki
2025-10-23 16:13:33 +02:00
Rafael J. Wysocki 05f084d24e Merge branches 'pm-core' and 'pm-runtime'
Merge runtime PM framework updates and a core power management code fix
for 6.18-rc1:

 - Make pm_runtime_put*() family of functions return 1 when the
   given device is already suspended which is consistent with the
   documentation (Brian Norris)

 - Add basic kunit tests for runtime PM API contracts and update return
   values in kerneldoc coments for the runtime PM API (Brian Norris,
   Dan Carpenter)

 - Add auto-cleanup macros for runtime PM "resume and get" and "get
   without resume" operations, use one of them in the PCI core and
   drop the existing "free" macro introduced for similar purpose, but
   somewhat cumbersome to use (Rafael Wysocki)

 - Make the core power management code avoid waiting on device links
   marked as SYNC_STATE_ONLY which is consistent with the handling of
   those device links elsewhere (Pin-yen Lin)

* pm-core:
  PM: sleep: Do not wait on SYNC_STATE_ONLY device links

* pm-runtime:
  PM: runtime: Fix error checking for kunit_device_register()
  PM: runtime: Introduce one more usage counter guard
  PM: runtime: Drop DEFINE_FREE() for pm_runtime_put()
  PCI/sysfs: Use runtime PM guard macro for auto-cleanup
  PM: runtime: Add auto-cleanup macros for "resume and get" operations
  PM: runtime: Update kerneldoc return codes
  PM: runtime: Make put{,_sync}() return 1 when already suspended
  PM: runtime: Add basic kunit tests for API contracts
2025-10-07 12:20:36 +02:00
Rafael J. Wysocki 9a0abc3945 PM: runtime: Add auto-cleanup macros for "resume and get" operations
It is generally useful to be able to automatically drop a device's
runtime PM usage counter incremented by runtime PM operations that
resume a device and bump up its usage counter [1].

To that end, add guard definition macros allowing pm_runtime_put()
and pm_runtime_put_autosuspend() to be used for the auto-cleanup in
those cases.

Simply put, a piece of code like below:

	pm_runtime_get_sync(dev);
	.....
	pm_runtime_put(dev);
	return 0;

can be transformed with guard() like:

	guard(pm_runtime_active)(dev);
	.....
	return 0;

(see the pm_runtime_put() call is gone).

However, it is better to do proper error handling in the majority of
cases, so doing something like this instead of the above is recommended:

	ACQUIRE(pm_runtime_active_try, pm)(dev);
	if (ACQUIRE_ERR(pm_runtime_active_try, &pm))
		return -ENXIO;
	.....
	return 0;

In all of the cases in which runtime PM is known to be enabled for the
given device or the device can be regarded as operational (and so it can
be accessed) with runtime PM disabled, a piece of code like:

	ret = pm_runtime_resume_and_get(dev);
	if (ret < 0)
		return ret;
	.....
	pm_runtime_put(dev);
	return 0;

can be changed as follows:

	ACQUIRE(pm_runtime_active_try, pm)(dev);
	ret = ACQUIRE_ERR(pm_runtime_active_try, &pm);
	if (ret < 0)
		return ret;
	.....
	return 0;

(again, see the pm_runtime_put() call is gone).

Still, if the device cannot be accessed unless runtime PM has been
enabled for it, the pm_runtime_active_try_enabled guard variant
needs to be used, that is (in the context of the example above):

	ACQUIRE(pm_runtime_active_try_enabled, pm)(dev);
	ret = ACQUIRE_ERR(pm_runtime_active_try_enabled, &pm);
	if (ret < 0)
		return ret;
	.....
	return 0;

When the original code calls pm_runtime_put_autosuspend(), use one
of the "auto" guard variants, pm_runtime_active_auto/_try/_enabled,
so for example, a piece of code like:

	ret = pm_runtime_resume_and_get(dev);
	if (ret < 0)
		return ret;
	.....
	pm_runtime_put_autosuspend(dev);
	return 0;

will become:

	ACQUIRE(pm_runtime_active_auto_try_enabled, pm)(dev);
	ret = ACQUIRE_ERR(pm_runtime_active_auto_try_enabled, &pm);
	if (ret < 0)
		return ret;
	.....
	return 0;

Note that the cases in which the return value of pm_runtime_get_sync()
is checked can also be handled with the help of the new guard macros.
For example, a piece of code like:

	ret = pm_runtime_get_sync(dev);
	if (ret < 0) {
		pm_runtime_put(dev);
		return ret;
	}
	.....
	pm_runtime_put(dev);
	return 0;

can be rewritten as:

	ACQUIRE(pm_runtime_active_auto_try_enabled, pm)(dev);
	ret = ACQUIRE_ERR(pm_runtime_active_auto_try_enabled, &pm);
	if (ret < 0)
		return ret;
	.....
	return 0;

or pm_runtime_get_active_try can be used if transparent handling of
disabled runtime PM is desirable.

Link: https://lore.kernel.org/linux-pm/878qimv24u.wl-tiwai@suse.de/ [1]
Link: https://lore.kernel.org/linux-pm/20250926150613.000073a4@huawei.com/
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/2238241.irdbgypaU6@rafael.j.wysocki
[ rjw: Fixed leftovers from the previous version in the changelog ]
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-29 17:00:21 +02:00
Brian NorrisandRafael J. Wysocki d0b8651a02 PM: runtime: Make put{,_sync}() return 1 when already suspended
The pm_runtime.h docs say pm_runtime_put() and pm_runtime_put_sync()
return 1 when already suspended, but this is not true -- they return
-EAGAIN. On the other hand, pm_runtime_put_sync_suspend() and
pm_runtime_put_sync_autosuspend() *do* return 1.

This is an artifact of the fact that the former are built on rpm_idle(),
whereas the latter are built on rpm_suspend().

There are precious few pm_runtime_put()/pm_runtime_put_sync() callers
that check the return code at all, but most of them only log errors, and
usually only for negative error codes. None of them should be treating
this as an error, so:

 * at best, this may fix some case where a driver treats this condition
   as an error, when it shouldn't;

 * at worst, this should make no effect; and

 * somewhere in between, we could potentially clear up non-fatal log
   messages.

Fix the pm_runtime_already_suspended_test() while tweaking the behavior.
The test makes a lot more sense when these all return 1 when the device
is already suspended:

    pm_runtime_put_sync(dev);
    pm_runtime_suspend(dev);
    pm_runtime_autosuspend(dev);
    pm_request_autosuspend(dev);
    pm_runtime_put_sync_autosuspend(dev);

Notably, I've avoided testing the return codes for these, since they
really should be ignored by callers, and we may make them 'void'
altogether:

    pm_runtime_put(dev);
    pm_runtime_put_autosuspend(dev);

Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-09-27 13:41:47 +02:00
Rafael J. Wysocki 3ce3f56999 PM: core: Add two macros for walking device links
Add separate macros for walking links to suppliers and consumers of a
device to help device links users to avoid exposing the internals of
struct dev_links_info in their code and possible coding mistakes related
to that.

Accordingly, use the new macros to replace open-coded device links list
walks in the core power management code.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/1944671.tdWV9SEqCh@rafael.j.wysocki
2025-09-06 17:16:32 +02:00
Rafael J. Wysocki fdd9ae23bb PM: core: Annotate loops walking device links as _srcu
Since SRCU is used for the protection of device link lists, the loops
over device link lists in multiple places in drivers/base/power/main.c
and in pm_runtime_get_suppliers() should be annotated as _srcu rather
than as _rcu which is the case currently.

Change the annotations accordingly.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/2393512.ElGaqSPkdT@rafael.j.wysocki
2025-09-06 17:16:06 +02:00
Linus Torvalds 22c5696e3f Merge tag 'driver-core-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core
Pull driver core updates from Danilo Krummrich:
 "debugfs:
   - Remove unneeded debugfs_file_{get,put}() instances
   - Remove last remnants of debugfs_real_fops()
   - Allow storing non-const void * in struct debugfs_inode_info::aux

  sysfs:
   - Switch back to attribute_group::bin_attrs (treewide)
   - Switch back to bin_attribute::read()/write() (treewide)
   - Constify internal references to 'struct bin_attribute'

  Support cache-ids for device-tree systems:
   - Add arch hook arch_compact_of_hwid()
   - Use arch_compact_of_hwid() to compact MPIDR values on arm64

  Rust:
   - Device:
       - Introduce CoreInternal device context (for bus internal methods)
       - Provide generic drvdata accessors for bus devices
       - Provide Driver::unbind() callbacks
       - Use the infrastructure above for auxiliary, PCI and platform
       - Implement Device::as_bound()
       - Rename Device::as_ref() to Device::from_raw() (treewide)
       - Implement fwnode and device property abstractions
       - Implement example usage in the Rust platform sample driver
   - Devres:
       - Remove the inner reference count (Arc) and use pin-init instead
       - Replace Devres::new_foreign_owned() with devres::register()
       - Require T to be Send in Devres<T>
       - Initialize the data kept inside a Devres last
       - Provide an accessor for the Devres associated Device
   - Device ID:
       - Add support for ACPI device IDs and driver match tables
       - Split up generic device ID infrastructure
       - Use generic device ID infrastructure in net::phy
   - DMA:
       - Implement the dma::Device trait
       - Add DMA mask accessors to dma::Device
       - Implement dma::Device for PCI and platform devices
       - Use DMA masks from the DMA sample module
   - I/O:
       - Implement abstraction for resource regions (struct resource)
       - Implement resource-based ioremap() abstractions
       - Provide platform device accessors for I/O (remap) requests
   - Misc:
       - Support fallible PinInit types in Revocable
       - Implement Wrapper<T> for Opaque<T>
       - Merge pin-init blanket dependencies (for Devres)

  Misc:
   - Fix OF node leak in auxiliary_device_create()
   - Use util macros in device property iterators
   - Improve kobject sample code
   - Add device_link_test() for testing device link flags
   - Fix typo in Documentation/ABI/testing/sysfs-kernel-address_bits
   - Hint to prefer container_of_const() over container_of()"

* tag 'driver-core-6.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: (84 commits)
  rust: io: fix broken intra-doc links to `platform::Device`
  rust: io: fix broken intra-doc link to missing `flags` module
  rust: io: mem: enable IoRequest doc-tests
  rust: platform: add resource accessors
  rust: io: mem: add a generic iomem abstraction
  rust: io: add resource abstraction
  rust: samples: dma: set DMA mask
  rust: platform: implement the `dma::Device` trait
  rust: pci: implement the `dma::Device` trait
  rust: dma: add DMA addressing capabilities
  rust: dma: implement `dma::Device` trait
  rust: net::phy Change module_phy_driver macro to use module_device_table macro
  rust: net::phy represent DeviceId as transparent wrapper over mdio_device_id
  rust: device_id: split out index support into a separate trait
  device: rust: rename Device::as_ref() to Device::from_raw()
  arm64: cacheinfo: Provide helper to compress MPIDR value into u32
  cacheinfo: Add arch hook to compress CPU h/w id into 32 bits for cache-id
  cacheinfo: Set cache 'id' based on DT data
  container_of: Document container_of() is not to be used in new code
  driver core: auxiliary bus: fix OF node leak
  ...
2025-07-29 12:15:39 -07:00
Rafael J. Wysocki 3b4d4c98e5 Merge branches 'pm-runtime' and 'pm-powercap'
Merge runtime PM updates and power capping updates for 6.17-rc1:

 - Document return values of suspend-related API functions in the
   runtime PM framework (Sakari Ailus)

 - Mark last busy stamp in multiple autosuspend-related functions in the
   runtime PM framework and update its documentation (Sakari Ailus)

 - Take active children into account in pm_runtime_get_if_in_use() for
   consistency (Rafael Wysocki)

 - Fix NULL pointer dereference in get_pd_power_uw() in the dtpm_cpu
   power capping driver (Sivan Zohar-Kotzer)

 - Add support for the Bartlett Lake platform to the Intel RAPL power
   capping driver (Qiao Wei)

 - Add PL4 support for Panther Lake to the intel_rapl_msr power capping
   driver (Zhang Rui)

* pm-runtime:
  PM: runtime: Take active children into account in pm_runtime_get_if_in_use()
  Documentation: PM: *_autosuspend() functions update last busy time
  PM: runtime: Mark last busy stamp in pm_request_autosuspend()
  PM: runtime: Mark last busy stamp in pm_runtime_autosuspend()
  PM: runtime: Mark last busy stamp in pm_runtime_put_sync_autosuspend()
  PM: runtime: Mark last busy stamp in pm_runtime_put_autosuspend()
  PM: runtime: Document return values of suspend-related API functions

* pm-powercap:
  powercap: dtpm_cpu: Fix NULL pointer dereference in get_pd_power_uw()
  powercap: intel_rapl: Add support for Bartlett Lake platform
  powercap: intel_rapl_msr: Add PL4 support for Panther Lake
2025-07-22 18:01:15 +02:00
Rafael J. Wysocki 51888393cc PM: runtime: Take active children into account in pm_runtime_get_if_in_use()
For all practical purposes, there is no difference between the situation
in which a given device is not ignoring children and its active child
count is nonzero and the situation in which its runtime PM usage counter
is nonzero.  However, pm_runtime_get_if_in_use() will only increment the
device's usage counter and return 1 in the latter case.

For consistency, make it do so in the former case either by adjusting
pm_runtime_get_conditional() and update the related kerneldoc comments
accordingly.

Fixes: c111566bea ("PM: runtime: Add pm_runtime_get_if_active()")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+: c0ef3df8db: PM: runtime: Simplify pm_runtime_get_if_active() usage
Cc: 5.10+ <stable@vger.kernel.org> # 5.10+
Link: https://patch.msgid.link/12700973.O9o76ZdvQC@rjwysocki.net
2025-07-15 15:03:25 +02:00
Rafael J. Wysocki ffda4ca460 PM: sleep: Add strict_midlayer flag to struct dev_pm_info
Add a new flag, called strict_midlayer, to struct dev_pm_info, along
with helper functions for updating and reading its value, to allow
middle layer code that provides proper callbacks for device suspend-
resume during system-wide PM transitions to let pm_runtime_force_suspend()
and and pm_runtime_force_resume() know that they should only invoke
runtime PM callbacks coming from the device's driver.

Namely, if this flag is set, pm_runtime_force_suspend() and
and pm_runtime_force_resume() will invoke runtime PM callbacks
provided by the device's driver directly with the assumption that
they have been called via a middle layer callback for device suspend
or resume, respectively.

For instance, acpi_general_pm_domain provides specific
callback functions for system suspend, acpi_subsys_suspend(),
acpi_subsys_suspend_late() and acpi_subsys_suspend_noirq(), and
it does not expect its runtime suspend callback function,
acpi_subsys_runtime_suspend(), to be invoked at any point during
system suspend. In particular, it does not expect that function
to be called from within any of the system suspend callback functions
mentioned above which would happen if a device driver collaborating
with acpi_general_pm_domain used pm_runtime_force_suspend() as its
callback function for any system suspend phase later than "prepare".

The new flag allows this expectation of acpi_general_pm_domain to
be formally expressed, which is going to be done subsequently.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/24017035.6Emhk5qWAg@rjwysocki.net
2025-07-03 17:10:40 +02:00
Rafael J. Wysocki 2b2dcf0811 PM: runtime: Introduce __rpm_get_driver_callback()
Add a special function for computing the address of the runtime PM
callback given by an offset relative to the start of the device
driver's struct dev_pm_ops and use it to obtain the driver callback
in __rpm_get_callback().

Also put the shared part of the callback address computation into a
separate helper function to avoid code duplication and explicit
pointer type casts.

The new __rpm_get_driver_callback() will be used subsequently for
implementing callback lookup in pm_runtime_force_suspend/resume().

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/2054356.usQuhbGJ8B@rjwysocki.net
2025-07-03 17:10:40 +02:00
Rafael J. Wysocki ab5ce09709 PM: Check power.needs_force_resume in pm_runtime_force_suspend()
Add a power.needs_force_resume check to pm_runtime_force_suspend() so
it need not rely on the runtime PM status of the device when deciding
whether or not to return early.

With the new check in place, pm_runtime_force_suspend() will also skip
devices with the runtime PM status equal to RPM_ACTIVE if they have
power.needs_force_resume set, so it won't need to change the RPM
status of the device to RPM_SUSPENDED in addition to setting
power.needs_force_resume in the case when pm_runtime_need_not_resume()
return false.

That allows the runtime PM status update to be removed from
pm_runtime_force_resume(), so the runtime PM status remains unchanged
between the pm_runtime_force_suspend() and pm_runtime_force_resume()
calls.

This change potentially unbreaks drivers that call pm_runtime_force_suspend()
from their ->remove() callbacks because currently, if the device being
unbound from its driver has a parent with enabled runtime PM and/or
(possibly) device links respecting runtime PM to suppliers, and it is
RPM_ACTIVE when the remove takes place, pm_runtime_force_suspend() will
not drop the parent's child count and the suppliers' runtime PM usage
counters after force-suspending the device unless pm_runtime_need_not_resume()
returns 'true' for it.  Moreover, because pm_runtime_force_suspend()
changes the device's runtime PM status to RPM_SUSPENDED, in the above
case pm_runtime_reinit() will not cause those counters to drop, so they
will remain nonzero forever effectively preventing the devices in
question from runtime-suspending going forward.

This change is also needed for pm_runtime_force_suspend() to work
with PCI PM and ACPI PM after subsequent changes.  Namely, say
DPM_FLAG_SMART_SUSPEND is set for a PCI device and its driver uses
pm_runtime_force_suspend() as its ->suspend() callback.  If
pm_runtime_force_suspend() changed the runtime PM status of the
device to RPM_SUSPENDED, pci_pm_suspend_noirq() would skip the
device due to the dev_pm_skip_suspend() check.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/1855933.VLH7GnMWUR@rjwysocki.net
2025-07-03 17:10:40 +02:00
Rafael J. Wysocki 89d9cec3b1 PM: runtime: Clear power.needs_force_resume in pm_runtime_reinit()
Clear power.needs_force_resume in pm_runtime_reinit() in case it has
been set by pm_runtime_force_suspend() invoked from a driver remove
callback.

Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/9495163.CDJkKcVGEf@rjwysocki.net
2025-07-03 17:10:40 +02:00
Rafael J. Wysocki e21bd84c2f PM: Make pm_runtime_force_resume() work with DPM_FLAG_SMART_SUSPEND
Curently, drivers using pm_runtime_force_suspend/resume() cannot set
DPM_FLAG_SMART_SUSPEND because the devices with that flag set may need
to be resumed during system-wide resume regardless of whether or not
they have power.needs_force_resume set.  That can happen due to a
dependency resolved at the beginning of a system-wide resume transition
(for instance, a bus type or PM domain has decided to resume a
subordinate device with DPM_FLAG_SMART_SUSPEND and its parent and
suppliers also need to be resumed).

To overcome this limitation, modify pm_runtime_force_resume() to check
the device's power.smart_suspend flag (which is set for devices with
DPM_FLAG_SMART_SUSPEND set that meet some additional requirements) and
the device's runtime PM status in addition to power.needs_force_resume.
Also change it to clear power.smart_suspend to ensure that it will not
handle the same device twice during one transition.

The underlying observation is that there are two cases in which the
device needs to be resumed by pm_runtime_force_resume().  One of them
is when the device has power.needs_force_resume set, which means that
pm_runtime_force_suspend() has suspended it and decided that it should
be resumed during the subsequent system resume.  The other one is when
power.smart_suspend is set and the device's runtume PM status is
RPM_ACTIVE.

Update kerneldoc comments in accordance with the code changes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/3662906.iIbC2pHGDl@rjwysocki.net
2025-07-03 17:10:40 +02:00
Rafael J. Wysocki c021c1b38f PM: Move two sleep-related functions under CONFIG_PM_SLEEP
Since pm_runtime_force_resume() and pm_runtime_need_not_resume() are only
needed for handling system-wide PM transitions, there is no reason to
compile them in if CONFIG_PM_SLEEP is unset.

Accordingly, move them under CONFIG_PM_SLEEP and make the static
inline stub for pm_runtime_force_resume() return an error to indicate
that it should not be used outside CONFIG_PM_SLEEP.

Putting pm_runtime_force_resume() also allows subsequent changes to
be more straightforward because this function is going to access a
device PM flag that is only defined when CONFIG_PM_SLEEP is set.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/3384523.aeNJFYEL58@rjwysocki.net
2025-07-03 17:10:40 +02:00
Rafael J. Wysocki 200046d827 PM: Use true/false as power.needs_force_resume values
Since power.needs_force_resume is a bool field, use true/false
as its values instead of 1/0, respectively.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/2254988.irdbgypaU6@rjwysocki.net
2025-07-03 17:10:40 +02:00
Rafael J. WysockiandGreg Kroah-Hartman b29929b819 driver core: Add device_link_test() for testing device link flags
To avoid coding mistakes like the one fixed by commit 3860cbe239 ("PM:
sleep: Fix bit masking operation"), introduce device_link_test() for
testing device link flags and use it where applicable.

No intentional functional impact.

Signed-off-by: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/2793309.mvXUDI8C0e@rjwysocki.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-06-17 10:57:56 +02:00
Charan Teja KallaandRafael J. Wysocki 40d3b40dce PM: runtime: fix denying of auto suspend in pm_suspend_timer_fn()
pm_runtime_put_autosuspend() schedules a hrtimer to expire
at "dev->power.timer_expires". If the hrtimer's callback,
pm_suspend_timer_fn(), observes that the current time equals
"dev->power.timer_expires", it unexpectedly bails out instead of
proceeding with runtime suspend.

pm_suspend_timer_fn():

 if (expires > 0 && expires < ktime_get_mono_fast_ns()) {
 	dev->power.timer_expires = 0;
 	rpm_suspend(..)
 }

Additionally, as ->timer_expires is not cleared, all the future auto
suspend requests will not schedule hrtimer to perform auto suspend.

rpm_suspend():

 if ((rpmflags & RPM_AUTO) &&...) {
 	if (!(dev->power.timer_expires && ...) { <-- this will fail.
 		hrtimer_start_range_ns(&dev->power.suspend_timer,...);
 	}
 }

Fix this by as well checking if current time reaches the set expiration.

Co-developed-by: Patrick Daly <quic_pdaly@quicinc.com>
Signed-off-by: Patrick Daly <quic_pdaly@quicinc.com>
Signed-off-by: Charan Teja Kalla <quic_charante@quicinc.com>
Link: https://patch.msgid.link/20250515064125.1211561-1-quic_charante@quicinc.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-05-16 22:05:43 +02:00
Bence CsókásandRafael J. Wysocki 73db799bf5 PM: runtime: Add new devm functions
Add `devm_pm_runtime_set_active_enabled()` and
`devm_pm_runtime_get_noresume()` for simplifying
common cases in drivers.

Signed-off-by: Bence Csókás <csokas.bence@prolan.hu>
Link: https://patch.msgid.link/20250327195928.680771-3-csokas.bence@prolan.hu
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-04-29 13:04:35 +02:00
Linus Torvalds 7d20aa5c32 Merge tag 'pm-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management updates from Rafael Wysocki:
 "These are dominated by cpufreq updates which in turn are dominated by
  updates related to boost support in the core and drivers and
  amd-pstate driver optimizations.

  Apart from the above, there are some cpuidle updates including a
  rework of the most recent idle intervals handling in the venerable
  menu governor that leads to significant improvements in some
  performance benchmarks, as the governor is now more likely to predict
  a shorter idle duration in some cases, and there are updates of the
  core device power management code, mostly related to system suspend
  and resume, that should help to avoid potential issues arising when
  the drivers of devices depending on one another want to use different
  optimizations.

  There is also a usual collection of assorted fixes and cleanups,
  including removal of some unused code.

  Specifics:

   - Manage sysfs attributes and boost frequencies efficiently from
     cpufreq core to reduce boilerplate code in drivers (Viresh Kumar)

   - Minor cleanups to cpufreq drivers (Aaron Kling, Benjamin Schneider,
     Dhananjay Ugwekar, Imran Shaik, zuoqian)

   - Migrate some cpufreq drivers to using for_each_present_cpu() (Jacky
     Bai)

   - cpufreq-qcom-hw DT binding fixes (Krzysztof Kozlowski)

   - Use str_enable_disable() helper in cpufreq_online() (Lifeng Zheng)

   - Optimize the amd-pstate driver to avoid cases where call paths end
     up calling the same writes multiple times and needlessly caching
     variables through code reorganization, locking overhaul and tracing
     adjustments (Mario Limonciello, Dhananjay Ugwekar)

   - Make it possible to avoid enabling capacity-aware scheduling (CAS)
     in the intel_pstate driver and relocate a check for out-of-band
     (OOB) platform handling in it to make it detect OOB before checking
     HWP availability (Rafael Wysocki)

   - Fix dbs_update() to avoid inadvertent conversions of negative
     integer values to unsigned int which causes CPU frequency selection
     to be inaccurate in some cases when the "conservative" cpufreq
     governor is in use (Jie Zhan)

   - Update the handling of the most recent idle intervals in the menu
     cpuidle governor to prevent useful information from being discarded
     by it in some cases and improve the prediction accuracy (Rafael
     Wysocki)

   - Make it possible to tell the intel_idle driver to ignore its
     built-in table of idle states for the given processor, clean up the
     handling of auto-demotion disabling on Baytrail and Cherrytrail
     chips in it, and update its MAINTAINERS entry (David Arcari, Artem
     Bityutskiy, Rafael Wysocki)

   - Make some cpuidle drivers use for_each_present_cpu() instead of
     for_each_possible_cpu() during initialization to avoid issues
     occurring when nosmp or maxcpus=0 are used (Jacky Bai)

   - Clean up the Energy Model handling code somewhat (Rafael Wysocki)

   - Use kfree_rcu() to simplify the handling of runtime Energy Model
     updates (Li RongQing)

   - Add an entry for the Energy Model framework to MAINTAINERS as
     properly maintained (Lukasz Luba)

   - Address RCU-related sparse warnings in the Energy Model code
     (Rafael Wysocki)

   - Remove ENERGY_MODEL dependency on SMP and allow it to be selected
     when DEVFREQ is set without CPUFREQ so it can be used on a wider
     range of systems (Jeson Gao)

   - Unify error handling during runtime suspend and runtime resume in
     the core to help drivers to implement more consistent runtime PM
     error handling (Rafael Wysocki)

   - Drop a redundant check from pm_runtime_force_resume() and rearrange
     documentation related to __pm_runtime_disable() (Rafael Wysocki)

   - Rework the handling of the "smart suspend" driver flag in the PM
     core to avoid issues hat may occur when drivers using it depend on
     some other drivers and clean up the related PM core code (Rafael
     Wysocki, Colin Ian King)

   - Fix the handling of devices with the power.direct_complete flag set
     if device_suspend() returns an error for at least one device to
     avoid situations in which some of them may not be resumed (Rafael
     Wysocki)

   - Use mutex_trylock() in hibernate_compressor_param_set() to avoid a
     possible deadlock that may occur if the "compressor" hibernation
     module parameter is accessed during the registration of a new
     ieee80211 device (Lizhi Xu)

   - Suppress sleeping parent warning in device_pm_add() in the case
     when new children are added under a device with the
     power.direct_complete set after it has been processed by
     device_resume() (Xu Yang)

   - Remove needless return in three void functions related to system
     wakeup (Zijun Hu)

   - Replace deprecated kmap_atomic() with kmap_local_page() in the
     hibernation core code (David Reaver)

   - Remove unused helper functions related to system sleep (David Alan
     Gilbert)

   - Clean up s2idle_enter() so it does not lock and unlock CPU offline
     in vain and update comments in it (Ulf Hansson)

   - Clean up broken white space in dpm_wait_for_children() (Geert
     Uytterhoeven)

   - Update the cpupower utility to fix lib version-ing in it and memory
     leaks in error legs, remove hard-coded values, and implement CPU
     physical core querying (Thomas Renninger, John B. Wyatt IV, Shuah
     Khan, Yiwei Lin, Zhongqiu Han)"

* tag 'pm-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (139 commits)
  PM: sleep: Fix bit masking operation
  dt-bindings: cpufreq: cpufreq-qcom-hw: Narrow properties on SDX75, SA8775p and SM8650
  dt-bindings: cpufreq: cpufreq-qcom-hw: Drop redundant minItems:1
  dt-bindings: cpufreq: cpufreq-qcom-hw: Add missing constraint for interrupt-names
  dt-bindings: cpufreq: cpufreq-qcom-hw: Add QCS8300 compatible
  cpufreq: Init cpufreq only for present CPUs
  PM: sleep: Fix handling devices with direct_complete set on errors
  cpuidle: Init cpuidle only for present CPUs
  PM: clk: Remove unused pm_clk_remove()
  PM: sleep: core: Fix indentation in dpm_wait_for_children()
  PM: s2idle: Extend comment in s2idle_enter()
  PM: s2idle: Drop redundant locks when entering s2idle
  PM: sleep: Remove unused pm_generic_ wrappers
  cpufreq: tegra186: Share policy per cluster
  cpupower: Make lib versioning scheme more obvious and fix version link
  PM: EM: Rework the depends on for CONFIG_ENERGY_MODEL
  PM: EM: Address RCU-related sparse warnings
  cpupower: Implement CPU physical core querying
  pm: cpupower: remove hard-coded topology depth values
  pm: cpupower: Fix cmd_monitor() error legs to free cpu_topology
  ...
2025-03-25 15:00:18 -07:00
Rafael J. Wysocki 5a98796468 Merge branch 'pm-sleep'
Merge updates related to system sleep for 6.15-rc1 including fixes,
cleanups and a rework of the "smart suspend" driver flag handling to
avoid issues that may occur when drivers using it depend on some other
drivers:

 - Rework the handling of the "smart suspend" driver flag in the PM core
   to avoid issues hat may occur when drivers using it depend on some
   other drivers and clean up the related PM core code (Rafael Wysocki,
   Colin Ian King).

 - Fix the handling of devices with the power.direct_complete flag set
   if device_suspend() returns an error for at least one device to avoid
   situations in which some of them may not be resumed (Rafael Wysocki).

 - Use mutex_trylock() in hibernate_compressor_param_set() to avoid a
   possible deadlock that may occur if the "compressor" hibernation
   module parameter is accessed during the registration of a new
   ieee80211 device (Lizhi Xu).

 - Suppress sleeping parent warning in device_pm_add() in the case when
   new children are added under a device with the power.direct_complete
   set after it has been processed by device_resume() (Xu Yang).

 - Remove needless return in three void functions related to system
   wakeup (Zijun Hu).

 - Replace deprecated kmap_atomic() with kmap_local_page() in the
   hibernation core code (David Reaver).

 - Remove unused helper functions related to system sleep (David Alan
   Gilbert).

 - Clean up s2idle_enter() so it does not lock and unlock CPU offline
   in vain and update comments in it (Ulf Hansson).

 - Clean up broken white space in dpm_wait_for_children() (Geert
   Uytterhoeven).

* pm-sleep:
  PM: sleep: Fix bit masking operation
  PM: sleep: Fix handling devices with direct_complete set on errors
  PM: sleep: core: Fix indentation in dpm_wait_for_children()
  PM: s2idle: Extend comment in s2idle_enter()
  PM: s2idle: Drop redundant locks when entering s2idle
  PM: sleep: Remove unused pm_generic_ wrappers
  PM: sleep: Rearrange dpm_async_fn() and async state clearing
  PM: sleep: Rename power.async_in_progress to power.work_in_progress
  PM: core: Tweak pm_runtime_block_if_disabled() return value
  PM: runtime: Convert pm_runtime_blocked() to static inline
  PM: sleep: Update power.smart_suspend under PM spinlock
  PM: sleep: Adjust check before setting power.must_resume
  PM: wakeup: Remove needless return in three void APIs
  PM: sleep: Suppress sleeping parent warning in special case
  PM: hibernate: Avoid deadlock in hibernate_compressor_param_set()
  PM: sleep: Avoid unnecessary checks in device_prepare_smart_suspend()
  PM: sleep: Use DPM_FLAG_SMART_SUSPEND conditionally
  PM: runtime: Introduce pm_runtime_blocked()
  PM: Block enabling of runtime PM during system suspend
  PM: hibernate: Replace deprecated kmap_atomic() with kmap_local_page()
2025-03-24 15:19:56 +01:00