Re: [PATCH] wlcore: sdio: Fix flakey SDIO runtime PM handling

[Tony Lindgren <tony@atomide.com>]

* Tony Lindgren <tony@atomide.com> [180515 15:46]:
> We can have pm_runtime_get_sync() return 1, and we can have
> pm_runtime_put_sync() return -EBUSY. See rpm_suspend() and
> rpm_resume() for more information.
> 
> Fix the issue by returning 0 from wl12xx_sdio_power_on() on success.
> And use pm_runtime_put() instead of pm_runtime_put_sync() for
> wl12xx_sdio_power_off(), then the MMC subsystem will idle the bus
> when suitable.
> 
> Otherwise wlcore can sometimes get confused and may report bogus
> errors and WLAN connection can fail.
> @@ -180,7 +180,7 @@ static int wl12xx_sdio_power_off(struct wl12xx_sdio_glue *glue)
>  	sdio_release_host(func);
>  
>  	/* Let runtime PM know the card is powered off */
> -	return pm_runtime_put_sync(&card->dev);
> +	return pm_runtime_put(&card->dev);
>  }

Looks like we can still get -EBUSY here though. I think we
can just ignore the return value of pm_runtime_put() here.

Regards,

Tony