mmc_spi: wait more bytes for card response

Some cards are slower than the standard allows and need more
time to respond to a command. Max. observed number of bytes
was 12.

Signed-off-by: Wolfgang Muees <wolfgang.mues@auerswald.de>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index ad9e0e213f64..69e1442ff2e2 100644
--- a/drivers/mmc/host/mmc_spi.c
+++ b/drivers/mmc/host/mmc_spi.c
@@ -279,8 +279,11 @@ static int mmc_spi_response_get(struct mmc_spi_host *host,
                  * so it can always DMA directly into the target buffer.
                  * It'd probably be better to memcpy() the first chunk and
                  * avoid extra i/o calls...
+                 *
+                 * Note we check for more than 8 bytes, because in practice,
+                 * some SD cards are slow...
                  */
-                for (i = 2; i < 9; i++) {
+                for (i = 2; i < 16; i++) {
                         value = mmc_spi_readbytes(host, 1);
                         if (value < 0)
                                 goto done;