mmc: rtsx_usb_sdmmc: Don't runtime resume the device while changing led

In case the card has been powered off, it seems silly to continue to allow
the led to be updated. Instead let's forbid that, as it enables us to
prevent runtime resuming the device and thus avoids wasting energy.
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>

drivers/mmc/host/rtsx_usb_sdmmc.c

@@ -1297,14 +1297,18 @@ static void rtsx_usb_update_led(struct work_struct *work)
 		container_of(work, struct rtsx_usb_sdmmc, led_work);
 	struct rtsx_ucr *ucr = host->ucr;
 
-	pm_runtime_get_sync(sdmmc_dev(host));
+	pm_runtime_get_noresume(sdmmc_dev(host));
 	mutex_lock(&ucr->dev_mutex);
 
+	if (host->power_mode == MMC_POWER_OFF)
+		goto out;
+
 	if (host->led.brightness == LED_OFF)
 		rtsx_usb_turn_off_led(ucr);
 	else
 		rtsx_usb_turn_on_led(ucr);
 
+out:
 	mutex_unlock(&ucr->dev_mutex);
 	pm_runtime_put(sdmmc_dev(host));
 }