From: Nathan Lynch nathanl@linux.ibm.com
[ Upstream commit 52719fce3f4c7a8ac9eaa191e8d75a697f9fbcbc ]
There are three ways pseries_suspend_begin() can be reached:
1. When "mem" is written to /sys/power/state:
kobj_attr_store() -> state_store() -> pm_suspend() -> suspend_devices_and_enter() -> pseries_suspend_begin()
This never works because there is no way to supply a valid stream id using this interface, and H_VASI_STATE is called with a stream id of zero. So this call path is useless at best.
2. When a stream id is written to /sys/devices/system/power/hibernate. pseries_suspend_begin() is polled directly from store_hibernate() until the stream is in the "Suspending" state (i.e. the platform is ready for the OS to suspend execution):
dev_attr_store() -> store_hibernate() -> pseries_suspend_begin()
3. When a stream id is written to /sys/devices/system/power/hibernate (continued). After #2, pseries_suspend_begin() is called once again from the pm core:
dev_attr_store() -> store_hibernate() -> pm_suspend() -> suspend_devices_and_enter() -> pseries_suspend_begin()
This is redundant because the VASI suspend state is already known to be Suspending.
The begin() callback of platform_suspend_ops is optional, so we can simply remove that assignment with no loss of function.
Fixes: 32d8ad4e621d ("powerpc/pseries: Partition hibernation support") Signed-off-by: Nathan Lynch nathanl@linux.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20201207215200.1785968-18-nathanl@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/platforms/pseries/suspend.c | 1 - 1 file changed, 1 deletion(-)
diff --git a/arch/powerpc/platforms/pseries/suspend.c b/arch/powerpc/platforms/pseries/suspend.c index f789693f61f40..0749ccb994002 100644 --- a/arch/powerpc/platforms/pseries/suspend.c +++ b/arch/powerpc/platforms/pseries/suspend.c @@ -190,7 +190,6 @@ static struct bus_type suspend_subsys = {
static const struct platform_suspend_ops pseries_suspend_ops = { .valid = suspend_valid_only_mem, - .begin = pseries_suspend_begin, .prepare_late = pseries_prepare_late, .enter = pseries_suspend_enter, };