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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-12-07 21:54:32 +0300 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2021-12-17 18:16:40 +0300 |
commit | c24efa6732788f0be22cdf5d2aedd5e3117e983f (patch) | |
tree | be9088b34899b2a67f9b98665a33d8579375bc47 /include/linux/pm.h | |
parent | 1a3c7bb088266fa2db017be299f91f1c1894c857 (diff) | |
download | linux-c24efa6732788f0be22cdf5d2aedd5e3117e983f.tar.xz |
PM: runtime: Capture device status before disabling runtime PM
In some cases (for example, during system-wide suspend and resume of
devices) it is useful to know whether or not runtime PM has ever been
enabled for a given device and, if so, what the runtime PM status of
it had been right before runtime PM was disabled for it last time.
For this reason, introduce a new struct dev_pm_info field called
last_status that will be used for capturing the runtime PM status of
the device when its power.disable_depth counter changes from 0 to 1.
The new field will be set to RPM_INVALID to start with and whenever
power.disable_depth changes from 1 to 0, so it will be valid only
when runtime PM of the device is currently disabled, but it has been
enabled at least once.
Immediately use power.last_status in rpm_resume() to make it handle
the case when PM runtime is disabled for the device, but its runtime
PM status is RPM_ACTIVE more consistently. Namely, make it return 1
if power.last_status is also equal to RPM_ACTIVE in that case (the
idea being that if the status was RPM_ACTIVE last time when
power.disable_depth was changing from 0 to 1 and it is still
RPM_ACTIVE, it can be assumed to reflect what happened to the device
last time when it was using runtime PM) and -EACCES otherwise.
Update the documentation to provide a description of last_status and
change the description of pm_runtime_resume() in it to reflect the
new behavior of rpm_active().
While at it, rearrange the code in pm_runtime_enable() to be more
straightforward and replace the WARN() macro in it with a pr_warn()
invocation which is less disruptive.
Link: https://lore.kernel.org/linux-pm/20211026222626.39222-1-ulf.hansson@linaro.org/t/#u
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/linux/pm.h')
-rw-r--r-- | include/linux/pm.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/pm.h b/include/linux/pm.h index fc9691cb01b4..e1e9402180b9 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -521,6 +521,7 @@ const struct dev_pm_ops __maybe_unused name = { \ */ enum rpm_status { + RPM_INVALID = -1, RPM_ACTIVE = 0, RPM_RESUMING, RPM_SUSPENDED, @@ -634,6 +635,7 @@ struct dev_pm_info { unsigned int links_count; enum rpm_request request; enum rpm_status runtime_status; + enum rpm_status last_status; int runtime_error; int autosuspend_delay; u64 last_busy; |