Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: - [Medium] accel: ethosu: double clock disable in ethosu_init() on PM enable failure --
commit f5f434ba4c9847ae5b3231ccf71531bf3ccbd16b Author: Rob Herring (Arm) <[email protected]> accel: ethosu: Disable clocks on PM setup failure This commit calls ethosu_device_suspend() on the error path when devm_pm_runtime_set_active_enabled() fails in ethosu_init(), aiming to disable the clocks that were enabled earlier by ethosu_device_resume(). > diff --git a/drivers/accel/ethosu/ethosu_drv.c > b/drivers/accel/ethosu/ethosu_drv.c > index 9ee144c41550c..1a65e9eef562f 100644 > --- a/drivers/accel/ethosu/ethosu_drv.c > +++ b/drivers/accel/ethosu/ethosu_drv.c > @@ -311,8 +311,10 @@ static int ethosu_init(struct ethosu_device *ethosudev) > pm_runtime_set_autosuspend_delay(ethosudev->base.dev, 50); > pm_runtime_use_autosuspend(ethosudev->base.dev); > ret = devm_pm_runtime_set_active_enabled(ethosudev->base.dev); > - if (ret) > + if (ret) { > + ethosu_device_suspend(ethosudev->base.dev); > return ret; > + } [Severity: Medium] Can this cause a double call to clk_bulk_disable_unprepare() on ethosudev->clks if devm_pm_runtime_set_active_enabled() fails inside devm_pm_runtime_enable()? In drivers/accel/ethosu/ethosu_drv.c:ethosu_init(), pm_runtime_use_autosuspend() is called and then devm_pm_runtime_set_active_enabled() runs while dev->power.usage_count is still 0, because pm_runtime_get_noresume() is only called after devm_pm_runtime_set_active_enabled() succeeds. Inside drivers/base/power/runtime.c:devm_pm_runtime_set_active_enabled(): int devm_pm_runtime_set_active_enabled(struct device *dev) { int err; err = pm_runtime_set_active(dev); if (err) return err; err = devm_add_action_or_reset(dev, pm_runtime_set_suspended_action, dev); if (err) return err; return devm_pm_runtime_enable(dev); } And in drivers/base/power/runtime.c:devm_pm_runtime_enable(): static void pm_runtime_disable_action(void *data) { pm_runtime_dont_use_autosuspend(data); pm_runtime_disable(data); } int devm_pm_runtime_enable(struct device *dev) { pm_runtime_enable(dev); return devm_add_action_or_reset(dev, pm_runtime_disable_action, dev); } If the devm_add_action_or_reset() allocation in devm_pm_runtime_enable() fails, it invokes pm_runtime_disable_action() while runtime PM is still enabled, runtime_status is RPM_ACTIVE, and usage_count is 0. pm_runtime_dont_use_autosuspend() clears use_autosuspend and calls update_autosuspend() -> rpm_idle() -> rpm_suspend(), which synchronously executes the runtime_suspend callback (ethosu_device_suspend()) and disables ethosudev->clks. When devm_pm_runtime_set_active_enabled() then returns the error to ethosu_init(), calling ethosu_device_suspend() unconditionally in the error path will disable and unprepare ethosudev->clks a second time. Would calling pm_runtime_get_noresume() before devm_pm_runtime_set_active_enabled() (and pairing it with pm_runtime_put_noidle() on error) prevent runtime PM from suspending the device during failure cleanup? -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=4
