PM: sleep: Fix possible deadlocks in core system-wide PM code
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Wed, 27 Dec 2023 20:41:06 +0000 (21:41 +0100)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Wed, 3 Jan 2024 11:05:38 +0000 (12:05 +0100)
commit7839d0078e0d5e6cc2fa0b0dfbee71de74f1e557
tree9cc0735e0856d625a10e3156832e3308678b0765
parent7d4b5d7a37bdd63a5a3371b988744b060d5bb86f
PM: sleep: Fix possible deadlocks in core system-wide PM code

It is reported that in low-memory situations the system-wide resume core
code deadlocks, because async_schedule_dev() executes its argument
function synchronously if it cannot allocate memory (and not only in
that case) and that function attempts to acquire a mutex that is already
held.  Executing the argument function synchronously from within
dpm_async_fn() may also be problematic for ordering reasons (it may
cause a consumer device's resume callback to be invoked before a
requisite supplier device's one, for example).

Address this by changing the code in question to use
async_schedule_dev_nocall() for scheduling the asynchronous
execution of device suspend and resume functions and to directly
run them synchronously if async_schedule_dev_nocall() returns false.

Link: https://lore.kernel.org/linux-pm/ZYvjiqX6EsL15moe@perf/
Reported-by: Youngmin Nam <youngmin.nam@samsung.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Tested-by: Youngmin Nam <youngmin.nam@samsung.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Cc: 5.7+ <stable@vger.kernel.org> # 5.7+: 6aa09a5bccd8 async: Split async_schedule_node_domain()
Cc: 5.7+ <stable@vger.kernel.org> # 5.7+: 7d4b5d7a37bd async: Introduce async_schedule_dev_nocall()
Cc: 5.7+ <stable@vger.kernel.org> # 5.7+
drivers/base/power/main.c