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Jiakai XuandGreg Kroah-Hartman
2fe7ebb3d5
[ Upstream commit3855941f1e] Replace complete_all() with complete() in device_pm_sleep_init() to allow it to be called in atomic contexts without triggering a false-positive WARNING from lockdep_assert_RT_in_threaded_ctx() when CONFIG_PROVE_RAW_LOCK_NESTING is enabled. device_pm_sleep_init() may be called during device initialization while holding a raw_spinlock (e.g., from within device_initialize()), and complete_all() is unsafe in atomic contexts on PREEMPT_RT kernels. complete(), which is safe to call from any context, is sufficient here. complete_all() sets the completion count to UINT_MAX/2 (permanently signaled), while complete() increments it by 1. Since no threads can be waiting during device initialization, both are functionally equivalent. The completion is always reinitialized via reinit_completion() in dpm_clear_async_state() before each suspend/resume cycle. However, changing to complete() introduces a potential deadlock for devices with no PM support (dev->power.no_pm = true). Such devices are never added to the dpm_list and never go through dpm_clear_async_state(), so their completion is never reinitialized. A parent device waiting on a no_pm child across multiple suspend phases would consume the single-use token in the first phase and block forever in the second. Fix this by adding an early return in dpm_wait() when dev->power.no_pm is set, since no_pm devices do not participate in system suspend/resume. Fixes:152e1d5920("PM: Prevent waiting forever on asynchronous resume after failing suspend") Signed-off-by: Jiakai Xu <xujiakai24@mails.ucas.ac.cn> [ rjw: Subject adjustment ] Link: https://patch.msgid.link/20260523022314.2657232-1-xujiakai24@mails.ucas.ac.cn Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org>