Re: [PATCH V3] input: Fix USB autosuspend on bcm5974

["Henrik Rydberg" <rydberg@euromail.se>]

> > I tried the patch out, unfortunately it did not work. The second
> > suspend request returns with a -EINPROGRESS, here:
> > 
> > 	if (dev->power.runtime_status == RPM_SUSPENDING) {
> > 		DEFINE_WAIT(wait);
> > 
> > 		if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
> > 			retval = -EINPROGRESS;
> > 			goto out;
> > 		}
> > 
> > 		/* Wait for the other suspend running in parallel with us. */
> > 		for (;;) {
> > 
> > The reason is above my horizon, although RPM_ASYNC looks suspicious.
> > In general, we are re-entering rpm_suspend from within the driver
> > handler, so the exit condition of rpm_suspend may not have been
> > satisfied yet.
> 
> Ah yes, I vaguely remember thinking that another part would have to be
> fixed.  But it's not just the part you identified; the error actually
> occurred higher up.  The patch below ought to help.

Yes, this works nicely, thank you. I attached my tested-by at the end,
presuming there will be a formal patch. :-)

>  drivers/base/power/runtime.c |   18 ++++++++++++------
>  1 file changed, 12 insertions(+), 6 deletions(-)
> 
> Index: usb-3.1/drivers/base/power/runtime.c
> ===================================================================
> --- usb-3.1.orig/drivers/base/power/runtime.c
> +++ usb-3.1/drivers/base/power/runtime.c
> @@ -278,8 +278,9 @@ static int rpm_callback(int (*cb)(struct
>   * @rpmflags: Flag bits.
>   *
>   * Check if the device's runtime PM status allows it to be suspended.  If
> - * another suspend has been started earlier, either return immediately or wait
> - * for it to finish, depending on the RPM_NOWAIT and RPM_ASYNC flags.  Cancel a
> + * another suspend has been started earlier and the RPM_ASYNC flag isn't set,
> + * either return immediately or wait for it to finish, depending on the
> + * RPM_NOWAIT flag.  Cancel a
>   * pending idle notification.  If the RPM_ASYNC flag is set then queue a
>   * suspend request; otherwise run the ->runtime_suspend() callback directly.
>   * If a deferred resume was requested while the callback was running then carry
> @@ -311,8 +312,7 @@ static int rpm_suspend(struct device *de
>  		goto out;
>  
>  	/* If the autosuspend_delay time hasn't expired yet, reschedule. */
> -	if ((rpmflags & RPM_AUTO)
> -	    && dev->power.runtime_status != RPM_SUSPENDING) {
> +	if (rpmflags & RPM_AUTO) {
>  		unsigned long expires = pm_runtime_autosuspend_expiration(dev);
>  
>  		if (expires != 0) {
> @@ -339,10 +339,16 @@ static int rpm_suspend(struct device *de
>  	/* Other scheduled or pending requests need to be canceled. */
>  	pm_runtime_cancel_pending(dev);
>  
> -	if (dev->power.runtime_status == RPM_SUSPENDING) {
> +	/*
> +	 * If the request is synchronous, wait for a concurrent suspend attempt
> +	 * to finish.  Allow asynchronous requests to go through; they will be
> +	 * cancelled if the concurrent suspend succeeds.
> +	 */
> +	if (dev->power.runtime_status == RPM_SUSPENDING &&
> +			!(rpmflags & RPM_ASYNC)) {
>  		DEFINE_WAIT(wait);
>  
> -		if (rpmflags & (RPM_ASYNC | RPM_NOWAIT)) {
> +		if (rpmflags & RPM_NOWAIT) {
>  			retval = -EINPROGRESS;
>  			goto out;
>  		}
> 

    Tested-by: Henrik Rydberg <rydberg@euromail.se>

Thanks,
Henrik