Re: [PATCH v2 1/2] PM: runtime: Only set runtime_error on suspend callback failures

[Rafael J. Wysocki (Intel)]

On Fri, Jul 3, 2026 at 5:05 PM Praveen Talari
<praveen.talari@xxxxxxxxxxxxxxxx> wrote:
>
> 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 transiently, there is no reason to
> permanently block future resume attempts on that device and all of its
> consumers.
>
> Fix this by conditioning the power.runtime_error assignment in
> rpm_callback() on the device being in the RPM_SUSPENDING state.  At the
> point rpm_callback() runs, __update_runtime_status() has already set the
> device status to either RPM_SUSPENDING or RPM_RESUMING, so the two paths
> are reliably distinguishable.  Suspend callback failures continue to set
> power.runtime_error as before.  Resume callback failures 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 | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c
> index 335288e8b5b3..70d933bcd295 100644
> --- a/drivers/base/power/runtime.c
> +++ b/drivers/base/power/runtime.c
> @@ -469,7 +469,13 @@ static int rpm_callback(int (*cb)(struct device *), struct device *dev)
>         if (retval == -EACCES)
>                 retval = -EAGAIN;
>
> -       if (retval != -EAGAIN && retval != -EBUSY)
> +       /*
> +        * Only stick the error on suspend failures.  Resume failures are not
> +        * treated as permanent so that the next resume attempt will run the
> +        * callback again rather than short-circuiting on runtime_error.
> +        */
> +       if (retval != -EAGAIN && retval != -EBUSY &&
> +           dev->power.runtime_status == RPM_SUSPENDING)
>                 dev->power.runtime_error = retval;

Why don't you move this check to rpm_suspend()?