From 33392343c74e417375b87032c66078a3bbc1dc91 Mon Sep 17 00:00:00 2001 From: Mayank Rungta Date: Wed, 9 Sep 2026 15:48:18 -0700 Subject: [PATCH] PM: sleep: Add DPM watchdog to prepare/late/early/noirq/complete phases Extend the DPM watchdog to wrap device_prepare, device_suspend_late, device_suspend_noirq, device_resume_noirq, device_resume_early, and device_complete callbacks. If a driver hangs during these transitions, the watchdog will fire and dump a stack trace to help identify the offending driver. To prevent false-positive timeouts, the watchdog is set only after waiting for subordinate (during suspend) and superior (during resume) devices. With this change, DPM watchdog coverage is extended across all phases of system sleep transitions. Signed-off-by: Mayank Rungta Reviewed-by: Douglas Anderson Reviewed-by: Tzung-Bi Shih Link: https://patch.msgid.link/20260909224818.2177311-1-mrungta@google.com Signed-off-by: Rafael J. Wysocki --- drivers/base/power/main.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index e130da428141..4e0d6357a37c 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -802,6 +802,7 @@ static void device_resume_noirq(struct device *dev, pm_message_t state, bool asy const char *info = NULL; bool skip_resume; int error = 0; + DECLARE_DPM_WATCHDOG_ON_STACK(wd); TRACE_DEVICE(dev); TRACE_RESUME(0); @@ -827,6 +828,7 @@ static void device_resume_noirq(struct device *dev, pm_message_t state, bool asy if (!dpm_wait_for_superior(dev, async)) goto Out; + dpm_watchdog_set(&wd, dev); skip_resume = dev_pm_skip_resume(dev); /* * If the driver callback is skipped below or by the middle layer @@ -871,6 +873,7 @@ static void device_resume_noirq(struct device *dev, pm_message_t state, bool asy error = dpm_run_callback(callback, dev, state, info); Skip: + dpm_watchdog_clear(&wd); dev->power.is_noirq_suspended = false; Out: @@ -971,6 +974,7 @@ static void device_resume_early(struct device *dev, pm_message_t state, bool asy pm_callback_t callback = NULL; const char *info = NULL; int error = 0; + DECLARE_DPM_WATCHDOG_ON_STACK(wd); TRACE_DEVICE(dev); TRACE_RESUME(0); @@ -987,6 +991,7 @@ static void device_resume_early(struct device *dev, pm_message_t state, bool asy if (!dpm_wait_for_superior(dev, async)) goto Out; + dpm_watchdog_set(&wd, dev); if (dev->pm_domain) { info = "early power domain "; callback = pm_late_early_op(&dev->pm_domain->ops, state); @@ -1004,7 +1009,7 @@ static void device_resume_early(struct device *dev, pm_message_t state, bool asy goto Run; if (dev_pm_skip_resume(dev)) - goto Skip; + goto End; if (dev->driver && dev->driver->pm) { info = "early driver "; @@ -1014,6 +1019,9 @@ static void device_resume_early(struct device *dev, pm_message_t state, bool asy Run: error = dpm_run_callback(callback, dev, state, info); +End: + dpm_watchdog_clear(&wd); + Skip: dev->power.is_late_suspended = false; pm_runtime_enable(dev); @@ -1281,10 +1289,12 @@ static void device_complete(struct device *dev, pm_message_t state) { void (*callback)(struct device *) = NULL; const char *info = NULL; + DECLARE_DPM_WATCHDOG_ON_STACK(wd); if (dev->power.syscore) goto out; + dpm_watchdog_set(&wd, dev); device_lock(dev); if (dev->pm_domain) { @@ -1312,6 +1322,7 @@ static void device_complete(struct device *dev, pm_message_t state) } device_unlock(dev); + dpm_watchdog_clear(&wd); out: /* If enabling runtime PM for the device is blocked, unblock it. */ @@ -1508,6 +1519,7 @@ static void device_suspend_noirq(struct device *dev, pm_message_t state, bool as pm_callback_t callback = NULL; const char *info = NULL; int error = 0; + DECLARE_DPM_WATCHDOG_ON_STACK(wd); TRACE_DEVICE(dev); TRACE_SUSPEND(0); @@ -1520,6 +1532,7 @@ static void device_suspend_noirq(struct device *dev, pm_message_t state, bool as if (dev->power.syscore || dev->power.direct_complete) goto Complete; + dpm_watchdog_set(&wd, dev); if (dev->pm_domain) { info = "noirq power domain "; callback = pm_noirq_op(&dev->pm_domain->ops, state); @@ -1550,7 +1563,7 @@ static void device_suspend_noirq(struct device *dev, pm_message_t state, bool as WRITE_ONCE(async_error, error); dpm_save_failed_dev(dev_name(dev)); pm_dev_err(dev, state, async ? " async noirq" : " noirq", error); - goto Complete; + goto End; } Skip: @@ -1569,6 +1582,9 @@ static void device_suspend_noirq(struct device *dev, pm_message_t state, bool as if (dev->power.must_resume) dpm_superior_set_must_resume(dev); +End: + dpm_watchdog_clear(&wd); + Complete: complete_all(&dev->power.completion); TRACE_SUSPEND(error); @@ -1703,6 +1719,7 @@ static void device_suspend_late(struct device *dev, pm_message_t state, bool asy pm_callback_t callback = NULL; const char *info = NULL; int error = 0; + DECLARE_DPM_WATCHDOG_ON_STACK(wd); TRACE_DEVICE(dev); TRACE_SUSPEND(0); @@ -1720,6 +1737,8 @@ static void device_suspend_late(struct device *dev, pm_message_t state, bool asy if (dev->power.direct_complete) goto Complete; + dpm_watchdog_set(&wd, dev); + /* * After this point, any runtime PM operations targeting the device * will fail until the corresponding pm_runtime_enable() call in @@ -1761,13 +1780,16 @@ static void device_suspend_late(struct device *dev, pm_message_t state, bool asy dpm_save_failed_dev(dev_name(dev)); pm_dev_err(dev, state, async ? " async late" : " late", error); pm_runtime_enable(dev); - goto Complete; + goto End; } dpm_propagate_wakeup_to_parent(dev); Skip: dev->power.is_late_suspended = true; +End: + dpm_watchdog_clear(&wd); + Complete: TRACE_SUSPEND(error); complete_all(&dev->power.completion); @@ -2201,6 +2223,7 @@ static int device_prepare(struct device *dev, pm_message_t state) int (*callback)(struct device *) = NULL; bool smart_suspend; int ret = 0; + DECLARE_DPM_WATCHDOG_ON_STACK(wd); /* * If a device's parent goes into runtime suspend at the wrong time, @@ -2220,6 +2243,7 @@ static int device_prepare(struct device *dev, pm_message_t state) if (dev->power.syscore) return 0; + dpm_watchdog_set(&wd, dev); device_lock(dev); dev->power.wakeup_path = false; @@ -2245,6 +2269,7 @@ static int device_prepare(struct device *dev, pm_message_t state) unlock: device_unlock(dev); + dpm_watchdog_clear(&wd); if (ret < 0) { suspend_report_result(dev, callback, ret);