mmc: sdio: ensure mmc_sdio_detect is powered

To prevent an erroneous removal of the card, make sure
the device is powered when it is mmc_sdio_detect()ed.

This is required since mmc_sdio_detect may be invoked
while the device is runtime suspended (e.g., MMC core
is rescanning when system comes out of suspend).
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Tested-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/core/sdio.c

@@ -546,6 +546,11 @@ static void mmc_sdio_detect(struct mmc_host *host)
 	BUG_ON(!host);
 	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;
+
 	mmc_claim_host(host);
 
 	/*
@@ -555,6 +560,7 @@ static void mmc_sdio_detect(struct mmc_host *host)
 
 	mmc_release_host(host);
 
+out:
 	if (err) {
 		mmc_sdio_remove(host);
 
@@ -562,6 +568,9 @@ static void mmc_sdio_detect(struct mmc_host *host)
 		mmc_detach_bus(host);
 		mmc_release_host(host);
 	}
+
+	/* Tell PM core that we're done */
+	pm_runtime_put(&host->card->dev);
 }
 
 /*