BACKPORT: FROMGIT: PM: runtime: add tracepoint for runtime_status changes
Existing runtime PM ftrace events (`rpm_suspend`, `rpm_resume`, `rpm_return_int`) offer limited visibility into the exact timing of device runtime power state transitions, particularly when asynchronous operations are involved. When the `rpm_suspend` or `rpm_resume` functions are invoked with the `RPM_ASYNC` flag, a return value of 0 i.e., success merely indicates that the device power state request has been queued, not that the device has yet transitioned. A new ftrace event, `rpm_status`, is introduced. This event directly logs the `power.runtime_status` value of a device whenever it changes providing granular tracking of runtime power state transitions regardless of synchronous or asynchronous `rpm_suspend` / `rpm_resume` usage. Signed-off-by:Vilas Bhat <vilasbhat@google.com> Signed-off-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com> Bug: 325508361 (cherry picked from commit 015abee4 https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next) [vilasbhat: Removed reference to RPM_INVALID from patch as it does not exist in 5.15] Change-Id: Iad7cae74c41b23b430331379c180b5e59bc32c40 Signed-off-by:
Vilas Bhat <vilasbhat@google.com>
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