linux/drivers/base
Tony Lindgren c745253e2a PM: runtime: Fix unpaired parent child_count for force_resume
As pm_runtime_need_not_resume() relies also on usage_count, it can return
a different value in pm_runtime_force_suspend() compared to when called in
pm_runtime_force_resume(). Different return values can happen if anything
calls PM runtime functions in between, and causes the parent child_count
to increase on every resume.

So far I've seen the issue only for omapdrm that does complicated things
with PM runtime calls during system suspend for legacy reasons:

omap_atomic_commit_tail() for omapdrm.0
 dispc_runtime_get()
  wakes up 58000000.dss as it's the dispc parent
   dispc_runtime_resume()
    rpm_resume() increases parent child_count
 dispc_runtime_put() won't idle, PM runtime suspend blocked
pm_runtime_force_suspend() for 58000000.dss, !pm_runtime_need_not_resume()
 __update_runtime_status()
system suspended
pm_runtime_force_resume() for 58000000.dss, pm_runtime_need_not_resume()
 pm_runtime_enable() only called because of pm_runtime_need_not_resume()
omap_atomic_commit_tail() for omapdrm.0
 dispc_runtime_get()
  wakes up 58000000.dss as it's the dispc parent
   dispc_runtime_resume()
    rpm_resume() increases parent child_count
 dispc_runtime_put() won't idle, PM runtime suspend blocked
...
rpm_suspend for 58000000.dss but parent child_count is now unbalanced

Let's fix the issue by adding a flag for needs_force_resume and use it in
pm_runtime_force_resume() instead of pm_runtime_need_not_resume().

Additionally omapdrm system suspend could be simplified later on to avoid
lots of unnecessary PM runtime calls and the complexity it adds. The
driver can just use internal functions that are shared between the PM
runtime and system suspend related functions.

Fixes: 4918e1f87c ("PM / runtime: Rework pm_runtime_force_suspend/resume()")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Cc: 4.16+ <stable@vger.kernel.org> # 4.16+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-05-10 19:14:01 +02:00
..
firmware_loader init/initramfs.c: do unpacking asynchronously 2021-05-07 00:26:33 -07:00
power PM: runtime: Fix unpaired parent child_count for force_resume 2021-05-10 19:14:01 +02:00
regmap regmap-irq: Fix dereference of a potentially null d->virt_buf 2021-04-07 16:58:33 +01:00
test kunit: software node: adhear to KUNIT formatting standard 2021-04-15 08:56:27 +02:00
arch_numa.c arch_numa: fix common code printing of phys_addr_t 2021-02-18 23:18:04 -08:00
arch_topology.c arch_topology: Export arch_freq_scale and helpers 2021-03-12 10:35:57 +05:30
attribute_container.c driver core: attribute_container: remove kernel-doc warnings 2021-04-02 16:40:07 +02:00
auxiliary.c driver core: auxiliary bus: Remove unneeded module bits 2021-03-23 10:47:55 +01:00
base.h driver core: Improve fw_devlink & deferred_probe_timeout interaction 2021-04-05 09:17:56 +02:00
bus.c drivers: base: change 'driver_create_groups' to 'driver_add_groups' in printk 2021-01-27 14:35:09 +01:00
cacheinfo.c drivers core: Use sysfs_emit for shared_cpu_map_show and shared_cpu_list_show 2020-10-02 13:24:40 +02:00
class.c drivers: base: fix some kernel-doc markups 2020-11-09 18:56:49 +01:00
component.c driver core: component: remove dentry pointer in "struct master" 2021-03-23 10:49:02 +01:00
container.c
core.c driver core: Improve fw_devlink & deferred_probe_timeout interaction 2021-04-05 09:17:56 +02:00
cpu.c drivers/base/cpu: remove redundant assignment of variable retval 2021-03-23 14:56:50 +01:00
dd.c Linux 5.12-rc7 2021-04-14 19:53:39 +02:00
devcoredump.c devcoredump: fix kernel-doc warning 2021-04-02 16:40:08 +02:00
devres.c driver core: Replace printf() specifier and drop unneeded casting 2021-04-02 17:02:45 +02:00
devtmpfs.c devtmpfs: actually reclaim some init memory 2021-03-23 14:57:35 +01:00
driver.c drivers: base: Convert to printk alias functions 2020-07-10 14:16:44 +02:00
firmware.c
hypervisor.c
init.c driver core: auxiliary bus: Fix calling stage for auxiliary bus init 2021-02-11 08:43:03 +01:00
isa.c isa: Make the remove callback for isa drivers return void 2021-01-26 07:42:27 +01:00
Kconfig RISC-V Patches for the 5.12 Merge Window 2021-02-26 10:28:35 -08:00
Makefile numa: Move numa implementation to common code 2021-01-14 15:08:55 -08:00
map.c
memory.c mm,memory_hotplug: allocate memmap from the added memory range 2021-05-05 11:27:26 -07:00
module.c
node.c node: fix device cleanups in error handling code 2021-04-10 11:10:21 +02:00
pinctrl.c
platform-msi.c platform-msi: fix kernel-doc warnings 2021-04-02 16:40:08 +02:00
platform.c Revert "driver core: platform: Make platform_get_irq_optional() optional" 2021-04-07 11:47:56 +02:00
property.c media: device property: Call fwnode_graph_get_endpoint_by_id() for fwnode->secondary 2021-01-26 19:24:18 +01:00
soc.c soc: fix comment for freeing soc_dev_attr 2020-12-09 19:46:31 +01:00
swnode.c software node: Allow node addition to already existing device 2021-04-15 10:36:07 +02:00
syscore.c syscore: Use pm_pr_dbg() for syscore_{suspend,resume}() 2020-09-08 13:32:06 +02:00
topology.c drivers core: Miscellaneous changes for sysfs_emit 2020-10-02 13:12:07 +02:00
transport_class.c scsi: drivers: base: Propagate errors through the transport component 2020-01-15 22:55:37 -05:00