[PATCH v4 1/2] PM: runtime: Only set runtime_error on suspend callback failures

[Praveen Talari]

When a runtime resume callback returns an error, rpm_callback() sets
power.runtime_error on the device.  This causes all subsequent calls to
rpm_resume() to return -EINVAL immediately at the top of the function
without invoking the callback again, making the failure permanent until
runtime PM is explicitly re-initialized.

Unlike suspend failures, resume failures should be retryable.  If a
device's resume callback fails, there is no reason to permanently block
future resume attempts on that device and all of its consumers.

Fix this by moving the power.runtime_error assignment out of the generic
rpm_callback() and into rpm_suspend() at its fail label, where suspend
callback failures are handled.  Resume callback failures now return the
error to the caller but leave power.runtime_error clear, allowing the
next resume attempt to invoke the callback normally.

Signed-off-by: Praveen Talari <praveen.talari@xxxxxxxxxxxxxxxx>
---
 drivers/base/power/runtime.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
index 335288e8b5b3..fab38bc98113 100644
--- a/drivers/base/power/runtime.c
+++ b/drivers/base/power/runtime.c
@@ -469,9 +469,6 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev)
 	if (retval == -EACCES)
 		retval = -EAGAIN;
 
-	if (retval != -EAGAIN && retval != -EBUSY)
-		dev->power.runtime_error = retval;
-
 	return retval;
 }
 
@@ -751,6 +748,9 @@ static int rpm_suspend(struct device *dev, int rpmflags)
 	dev->power.deferred_resume = false;
 	wake_up_all(&dev->power.wait_queue);
 
+	if (retval != -EAGAIN && retval != -EBUSY)
+		dev->power.runtime_error = retval;
+
 	/*
 	 * On transient errors, if the callback routine failed an autosuspend,
 	 * and if the last_busy time has been updated so that there is a new

-- 
2.34.1