1 files changed, 24 insertions, 3 deletions

diff --git a/drivers/mmc/host/mmc_spi.c b/drivers/mmc/host/mmc_spi.c
index 69e1442ff2e2..72f8bde4877a 100644
--- a/drivers/mmc/host/mmc_spi.c
+++ b/drivers/mmc/host/mmc_spi.c
@@ -612,6 +612,7 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t,
         struct spi_device       *spi = host->spi;
         int                     status, i;
         struct scratch          *scratch = host->data;
+        u32                     pattern;
 
         if (host->mmc->use_spi_crc)
                 scratch->crc_val = cpu_to_be16(
@@ -639,8 +640,27 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t,
          * doesn't necessarily tell whether the write operation succeeded;
          * it just says if the transmission was ok and whether *earlier*
          * writes succeeded; see the standard.
+         *
+         * In practice, there are (even modern SDHC-)cards which are late
+         * in sending the response, and miss the time frame by a few bits,
+         * so we have to cope with this situation and check the response
+         * bit-by-bit. Arggh!!!
          */
-        switch (SPI_MMC_RESPONSE_CODE(scratch->status[0])) {
+        pattern  = scratch->status[0] << 24;
+        pattern |= scratch->status[1] << 16;
+        pattern |= scratch->status[2] << 8;
+        pattern |= scratch->status[3];
+
+        /* First 3 bit of pattern are undefined */
+        pattern |= 0xE0000000;
+
+        /* left-adjust to leading 0 bit */
+        while (pattern & 0x80000000)
+                pattern <<= 1;
+        /* right-adjust for pattern matching. Code is in bit 4..0 now. */
+        pattern >>= 27;
+
+        switch (pattern) {
         case SPI_RESPONSE_ACCEPTED:
                 status = 0;
                 break;
@@ -671,8 +691,9 @@ mmc_spi_writeblock(struct mmc_spi_host *host, struct spi_transfer *t,
         /* Return when not busy.  If we didn't collect that status yet,
          * we'll need some more I/O.
          */
-        for (i = 1; i < sizeof(scratch->status); i++) {
-                if (scratch->status[i] != 0)
+        for (i = 4; i < sizeof(scratch->status); i++) {
+                /* card is non-busy if the most recent bit is 1 */
+                if (scratch->status[i] & 0x01)
                         return 0;
         }
         return mmc_spi_wait_unbusy(host, timeout);