mmc: add MMC_QUIRK_NONSTD_FUNC_IF

Introduce MMC_QUIRK_NONSTD_FUNC_IF to ignore the "SDIO Standard Function
interface code" as indicated by the card's FBR, and instead treat all
functions as non-standard interfaces.

This is required to prevent standard drivers from facing
errors when trying to communicate with SDIO cards that erroneously
indicate standard function interface codes.

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

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 4221670bf82..c3c2bd0874e 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -16,6 +16,7 @@
 #include <linux/mmc/card.h>
 #include <linux/mmc/sdio.h>
 #include <linux/mmc/sdio_func.h>
+#include <linux/mmc/sdio_ids.h>
 
 #include "core.h"
 #include "bus.h"
@@ -31,6 +32,11 @@ static int sdio_read_fbr(struct sdio_func *func)
         int ret;
         unsigned char data;
 
+        if (mmc_card_nonstd_func_interface(func->card)) {
+                func->class = SDIO_CLASS_NONE;
+                return 0;
+        }
+
         ret = mmc_io_rw_direct(func->card, 0, 0,
                 SDIO_FBR_BASE(func->num) + SDIO_FBR_STD_IF, 0, &data);
         if (ret)