mmc: propagate error codes back from bus drivers' suspend/resume methods

Especially for SDIO drivers which may have special conditions/errors to
report, it is a good thing to relay the returned error code back to upper
layers.

This also allows for the rationalization of the resume path where code to
"remove" a no-longer-existing or replaced card was duplicated into the
MMC, SD and SDIO bus drivers.

In the SDIO case, if a function suspend method returns an error, then all
previously suspended functions are resumed and the error returned.  An
exception is made for -ENOSYS which the core interprets as "we don't
support suspend so just kick the card out for suspend and return success".

When resuming SDIO cards, the core code only validates the manufacturer
and product IDs to make sure the same kind of card is still present before
invoking functions resume methods.  It's the function driver's
responsibility to perform further tests to confirm that the actual same
card is present (same MAC address, etc.) and return an error otherwise.

Signed-off-by: Nicolas Pitre <nico@marvell.com>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 10 deletions

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index ddddad46b402..bfefce365ae7 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -530,7 +530,7 @@ static void mmc_detect(struct mmc_host *host)
 /*
  * Suspend callback from host.
  */
-static void mmc_suspend(struct mmc_host *host)
+static int mmc_suspend(struct mmc_host *host)
 {
 	BUG_ON(!host);
 	BUG_ON(!host->card);
@@ -540,6 +540,8 @@ static void mmc_suspend(struct mmc_host *host)
 		mmc_deselect_cards(host);
 	host->card->state &= ~MMC_STATE_HIGHSPEED;
 	mmc_release_host(host);
+
+	return 0;
 }
 
 /*
@@ -548,7 +550,7 @@ static void mmc_suspend(struct mmc_host *host)
  * This function tries to determine if the same card is still present
  * and, if so, restore all state to it.
  */
-static void mmc_resume(struct mmc_host *host)
+static int mmc_resume(struct mmc_host *host)
 {
 	int err;
 
@@ -559,14 +561,7 @@ static void mmc_resume(struct mmc_host *host)
 	err = mmc_init_card(host, host->ocr, host->card);
 	mmc_release_host(host);
 
-	if (err) {
-		mmc_remove(host);
-
-		mmc_claim_host(host);
-		mmc_detach_bus(host);
-		mmc_release_host(host);
-	}
-
+	return err;
 }
 
 static void mmc_power_restore(struct mmc_host *host)