mmc: sdio: fix runtime PM anomalies by introducing MMC_CAP_POWER_OFF_CARD
Some board/card/host configurations are not capable of powering off the
card after boot.
To support such configurations, and to allow smoother transition to
runtime PM behavior, MMC_CAP_POWER_OFF_CARD is added, so hosts need to
explicitly indicate whether it's OK to power off their cards after boot.
SDIO core will enable runtime PM for a card only if that cap is set.
As a result, the card will be powered down after boot, and will only
be powered up again when a driver is loaded (and then it's up to the
driver to decide whether power will be kept or not).
This will prevent sdio_bus_probe() failures with setups that do not
support powering off the card.
Reported-and-tested-by: Daniel Drake <dsd@laptop.org>
Reported-and-tested-by: Arnd Hannemann <arnd@arndnet.de>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 42a949b..efef5f9 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -547,9 +547,11 @@
BUG_ON(!host->card);
/* Make sure card is powered before detecting it */
- err = pm_runtime_get_sync(&host->card->dev);
- if (err < 0)
- goto out;
+ if (host->caps & MMC_CAP_POWER_OFF_CARD) {
+ err = pm_runtime_get_sync(&host->card->dev);
+ if (err < 0)
+ goto out;
+ }
mmc_claim_host(host);
@@ -571,7 +573,8 @@
* is about to show up at this point, the _sync variant is
* desirable anyway.
*/
- pm_runtime_put_sync(&host->card->dev);
+ if (host->caps & MMC_CAP_POWER_OFF_CARD)
+ pm_runtime_put_sync(&host->card->dev);
out:
if (err) {
@@ -728,16 +731,21 @@
card = host->card;
/*
- * Let runtime PM core know our card is active
+ * Enable runtime PM only if supported by host+card+board
*/
- err = pm_runtime_set_active(&card->dev);
- if (err)
- goto remove;
+ if (host->caps & MMC_CAP_POWER_OFF_CARD) {
+ /*
+ * Let runtime PM core know our card is active
+ */
+ err = pm_runtime_set_active(&card->dev);
+ if (err)
+ goto remove;
- /*
- * Enable runtime PM for this card
- */
- pm_runtime_enable(&card->dev);
+ /*
+ * Enable runtime PM for this card
+ */
+ pm_runtime_enable(&card->dev);
+ }
/*
* The number of functions on the card is encoded inside
@@ -755,9 +763,10 @@
goto remove;
/*
- * Enable Runtime PM for this func
+ * Enable Runtime PM for this func (if supported)
*/
- pm_runtime_enable(&card->sdio_func[i]->dev);
+ if (host->caps & MMC_CAP_POWER_OFF_CARD)
+ pm_runtime_enable(&card->sdio_func[i]->dev);
}
mmc_release_host(host);