mirror_ubuntu-kernels/include
Rafael J. Wysocki c24efa6732 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>
2021-12-17 16:16:40 +01:00
..
acpi Merge branches 'acpica', 'acpi-ec', 'acpi-pmic' and 'acpi-video' 2021-11-10 14:03:14 +01:00
asm-generic Add linux/cacheflush.h 2021-11-17 10:36:15 -05:00
clocksource
crypto
drm Removed the TTM Huge Page functionnality to address a crash, a timeout 2021-11-11 08:14:19 +10:00
dt-bindings dt-bindings: Rename Ingenic CGU headers to ingenic,*.h 2021-11-11 22:27:14 -06:00
keys
kunit include/kunit/test.h: replace kernel.h with the necessary inclusions 2021-11-09 10:02:49 -08:00
kvm
linux PM: runtime: Capture device status before disabling runtime PM 2021-12-17 16:16:40 +01:00
math-emu
media Merge branch 'akpm' (patches from Andrew) 2021-11-09 10:11:53 -08:00
memory
misc
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2021-12-08 17:02:35 -08:00
pcmcia
ras
rdma RDMA/netlink: Add __maybe_unused to static inline in C file 2021-11-16 13:13:08 -04:00
scsi SCSI misc on 20211112 2021-11-12 12:25:50 -08:00
soc net: mscc: ocelot: create a function that replaces an existing VCAP filter 2021-11-26 11:38:20 -08:00
sound ASoC: Fixes for v5.16 2021-11-25 14:35:24 +01:00
target
trace NFS client bugfixes for Linux 5.16 2021-11-27 10:33:55 -08:00
uapi Merge branch 'akpm' (patches from Andrew) 2021-12-11 08:46:52 -08:00
vdso
video
xen xen: add "not_essential" flag to struct xenbus_driver 2021-11-23 13:41:29 -06:00