mmc: sdio: don't reinitialize nonremovable powered-resumed cards

Upon system resume, SDIO core must reinitialize cards that were
powered off during suspend.

If the card had its power kept during suspend (and thus it is
'powered-resumed'), SDIO core performs only a limited reinitializing,
mainly needed to make sure that the card wasn't removed/replaced.

If a __nonremovable__ card is powered-resumed, we can safely skip the
reinitializing phase.

Note: 9b966aae (mmc: sdio: fully reconfigure oldcard on resume) removed
the bus width reconfiguration since mmc_sdio_init_card already does it.
It is brought back now in case mmc_sdio_init_card is skipped.
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/core/sdio.c

@@ -627,15 +627,27 @@ static int mmc_sdio_suspend(struct mmc_host *host)
 
 static int mmc_sdio_resume(struct mmc_host *host)
 {
-	int i, err;
+	int i, err = 0;
 
 	BUG_ON(!host);
 	BUG_ON(!host->card);
 
 	/* Basic card reinitialization. */
 	mmc_claim_host(host);
+
+	/* No need to reinitialize powered-resumed nonremovable cards */
+	if (mmc_card_is_removable(host) || !mmc_card_is_powered_resumed(host))
 		err = mmc_sdio_init_card(host, host->ocr, host->card,
 				 (host->pm_flags & MMC_PM_KEEP_POWER));
+	else if (mmc_card_is_powered_resumed(host)) {
+		/* We may have switched to 1-bit mode during suspend */
+		err = sdio_enable_4bit_bus(host->card);
+		if (err > 0) {
+			mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
+			err = 0;
+		}
+	}
+
 	if (!err && host->sdio_irqs)
 		mmc_signal_sdio_irq(host);
 	mmc_release_host(host);

include/linux/mmc/host.h

@@ -320,5 +320,10 @@ static inline int mmc_card_is_removable(struct mmc_host *host)
 	return !(host->caps & MMC_CAP_NONREMOVABLE) && mmc_assume_removable;
 }
 
+static inline int mmc_card_is_powered_resumed(struct mmc_host *host)
+{
+	return host->pm_flags & MMC_PM_KEEP_POWER;
+}
+
 #endif