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| author |  Richard Fitzgerald <rf@opensource.cirrus.com>
| 2022-12-13 15:54:48 +0000 |
|---|---|---|
| committer |  Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| 2023-01-13 20:53:44 +0100 |
| commit | 450316dc4f41e857c928dfbcc495c3810d4b1928 (patch) | |
| tree | 8c5c920e2389a0920c6dc1f0ac2f068e8cb34e17 | |
| parent | Linux 6.2-rc3 (diff) | |
| download | linux-450316dc4f41e857c928dfbcc495c3810d4b1928.tar.gz linux-450316dc4f41e857c928dfbcc495c3810d4b1928.tar.bz2 linux-450316dc4f41e857c928dfbcc495c3810d4b1928.zip | |
PM: runtime: Document that force_suspend() is incompatible with SMART_SUSPEND
pm_runtime_force_suspend() cannot be used with DPM_FLAG_SMART_SUSPEND, so
note this in the kerneldoc.
If DPM_FLAG_SMART_SUSPEND is set and the PM core cannot skip system resume
it will call pm_runtime_active() on the driver. This can lead to an
inconsistent state where:
pm_runtime_force_suspend() called ->runtime_suspend
but
device_resume_noirq() called pm_runtime_set_active()
This leaves the driver actually suspended but marked as active.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/base/power/runtime.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 50e726b6c2cf..b29be7d4d7d0 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1864,6 +1864,10 @@ static bool pm_runtime_need_not_resume(struct device *dev) * sure the device is put into low power state and it should only be used during * system-wide PM transitions to sleep states. It assumes that the analogous * pm_runtime_force_resume() will be used to resume the device. + * + * Do not use with DPM_FLAG_SMART_SUSPEND as this can lead to an inconsistent + * state where this function has called the ->runtime_suspend callback but the + * PM core marks the driver as runtime active. */ int pm_runtime_force_suspend(struct device *dev) { |