6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shibo Zhu <3499129952@qq.com> [ Upstream commit cb258d651d747a7f7063d40f145418bee562ceaf ] device_prepare() blocks runtime PM for a device with runtime PM disabled before invoking its system-sleep ->prepare() callback. For a device that has never enabled runtime PM, this changes dev->power.last_status from RPM_INVALID to RPM_BLOCKED. If the callback returns an error, dpm_prepare() does not move the device to dpm_prepared_list. Consequently, the recovery path through dpm_complete() never calls device_complete() for the failing device. The error path drops the runtime PM usage reference, but does not clear RPM_BLOCKED. A later legitimate pm_runtime_enable() then reports: Attempt to enable runtime PM when it is blocked before clearing the stale state. Call pm_runtime_unblock() on the prepare error path before dropping the runtime PM reference, matching the cleanup performed by device_complete(). The issue was reproduced with a platform test device whose ->prepare() callback returns -EIO while runtime PM has never been enabled. Before the fix, last_status remained RPM_BLOCKED after the failed suspend and the first pm_runtime_enable() produced the warning above. With the fix, last_status is restored to RPM_INVALID and the warning is absent. Fixes: 3e5eee147b7b ("PM: Block enabling of runtime PM during system suspend") Cc: All applicable Signed-off-by: Shibo Zhu <3499129952@qq.com> Link: https://patch.msgid.link/tencent_C5AC0A02FC01F700E764F8C2E3ECE4F41009@qq.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/base/power/main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index fab8df1e29e62..ab240ccf7fd41 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -1888,6 +1888,7 @@ static int device_prepare(struct device *dev, pm_message_t state) if (ret < 0) { suspend_report_result(dev, callback, ret); + pm_runtime_unblock(dev); pm_runtime_put(dev); return ret; } -- 2.53.0