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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2021-12-07 21:54:32 +0300
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2021-12-17 18:16:40 +0300
commitc24efa6732788f0be22cdf5d2aedd5e3117e983f (patch)
treebe9088b34899b2a67f9b98665a33d8579375bc47 /include/linux/pm.h
parent1a3c7bb088266fa2db017be299f91f1c1894c857 (diff)
downloadlinux-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.h2
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;