mmc: skip detection of nonremovable cards on rescan

mmc_rescan() checks whether registered cards are still present before
skipping them, by calling the bus-specific ->detect() handler.

With buses that support runtime PM, the card may be powered off at
this point, so they need to be powered on and fully reinitialized before
->detect() executes.

This whole process is redundant with nonremovable cards; in those cases,
we can safely skip calling ->detect() and implicitly assume its success.

Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Reviewed-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 722af2dce3bb..9683d4d3fced 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1506,8 +1506,12 @@ void mmc_rescan(struct work_struct *work)
 
         mmc_bus_get(host);
 
-        /* if there is a card registered, check whether it is still present */
-        if ((host->bus_ops != NULL) && host->bus_ops->detect && !host->bus_dead)
+        /*
+         * if there is a _removable_ card registered, check whether it is
+         * still present
+         */
+        if (host->bus_ops && host->bus_ops->detect && !host->bus_dead
+            && mmc_card_is_removable(host))
                 host->bus_ops->detect(host);
 
         mmc_bus_put(host);