forked from luck/tmp_suning_uos_patched
4c06c4e6cf
If a stateless device link to a certain supplier with
DL_FLAG_PM_RUNTIME set in the flags is added and then removed by the
consumer driver's probe callback, the supplier's PM-runtime usage
counter will be nonzero after that which effectively causes the
supplier to remain "always on" going forward.
Namely, device_link_add() called to add the link invokes
device_link_rpm_prepare() which notices that the consumer driver is
probing, so it increments the supplier's PM-runtime usage counter
with the assumption that the link will stay around until
pm_runtime_put_suppliers() is called by driver_probe_device(),
but if the link goes away before that point, the supplier's
PM-runtime usage counter will remain nonzero.
To prevent that from happening, first rework pm_runtime_get_suppliers()
and pm_runtime_put_suppliers() to use the rpm_active refounts of device
links and make the latter only drop rpm_active and the supplier's
PM-runtime usage counter for each link by one, unless rpm_active is
one already for it. Next, modify device_link_add() to bump up the
new link's rpm_active refcount and the suppliers PM-runtime usage
counter by two, to prevent pm_runtime_put_suppliers(), if it is
called subsequently, from suspending the supplier prematurely (in
case its PM-runtime usage counter goes down to 0 in there).
Due to the way rpm_put_suppliers() works, this change does not
affect runtime suspend of the consumer ends of new device links (or,
generally, device links for which DL_FLAG_PM_RUNTIME has just been
set).
Fixes:
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.. | ||
firmware_loader | ||
power | ||
regmap | ||
test | ||
arch_topology.c | ||
attribute_container.c | ||
base.h | ||
bus.c | ||
cacheinfo.c | ||
class.c | ||
component.c | ||
container.c | ||
core.c | ||
cpu.c | ||
dd.c | ||
devcon.c | ||
devcoredump.c | ||
devres.c | ||
devtmpfs.c | ||
driver.c | ||
firmware.c | ||
hypervisor.c | ||
init.c | ||
isa.c | ||
Kconfig | ||
Makefile | ||
map.c | ||
memory.c | ||
module.c | ||
node.c | ||
pinctrl.c | ||
platform-msi.c | ||
platform.c | ||
property.c | ||
soc.c | ||
swnode.c | ||
syscore.c | ||
topology.c | ||
transport_class.c |