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Wysocki" , Greg Kroah-Hartman , Danilo Krummrich Cc: Len Brown , Pavel Machek , Douglas Anderson , Tzung-Bi Shih , linux-pm@vger.kernel.org, driver-core@lists.linux.dev, linux-kernel@vger.kernel.org, Mayank Rungta Content-Type: text/plain; charset="UTF-8" Extend the DPM watchdog to wrap device_suspend_late, device_suspend_noirq, device_resume_early, and device_resume_noirq 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. Signed-off-by: Mayank Rungta --- Testing: - Tested on an ARM64 SoC (Pixel platform running a 6.18-based kernel with DPM watchdog enabled; Android 6.18 kernel has latest DPM changes backported). drivers/base/power/main.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 184dc4b3b938..b6778700af28 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); @@ -1508,6 +1516,7 @@ 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 +1529,7 @@ 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 +1560,7 @@ 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 +1579,9 @@ 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 +1716,7 @@ 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 +1734,8 @@ 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 +1777,16 @@ 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); base-commit: 77ae27fd98f3b548797c9f22c10ab5cf1c4ada53 -- 2.55.0.766.g2966f0265a-goog