[MMC] extend data timeout for writes

The CSD contains a "read2write factor" which determines the multiplier to
be applied to the read timeout to obtain the write timeout.  We were
ignoring this parameter, resulting in the possibility for writes being
timed out too early.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 8 insertions, 0 deletions

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index da6ddd910fc5..05aa4d6b4f24 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -549,6 +549,7 @@ static void mmc_decode_csd(struct mmc_card *card)
                 csd->read_partial = UNSTUFF_BITS(resp, 79, 1);
                 csd->write_misalign = UNSTUFF_BITS(resp, 78, 1);
                 csd->read_misalign = UNSTUFF_BITS(resp, 77, 1);
+                csd->r2w_factor = UNSTUFF_BITS(resp, 26, 3);
                 csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4);
                 csd->write_partial = UNSTUFF_BITS(resp, 21, 1);
         } else {
@@ -583,6 +584,7 @@ static void mmc_decode_csd(struct mmc_card *card)
                 csd->read_partial = UNSTUFF_BITS(resp, 79, 1);
                 csd->write_misalign = UNSTUFF_BITS(resp, 78, 1);
                 csd->read_misalign = UNSTUFF_BITS(resp, 77, 1);
+                csd->r2w_factor = UNSTUFF_BITS(resp, 26, 3);
                 csd->write_blkbits = UNSTUFF_BITS(resp, 22, 4);
                 csd->write_partial = UNSTUFF_BITS(resp, 21, 1);
         }
diff --git a/drivers/mmc/mmc_block.c b/drivers/mmc/mmc_block.c
index 8eb2a2ede64b..06bd1f4cb9b1 100644
--- a/drivers/mmc/mmc_block.c
+++ b/drivers/mmc/mmc_block.c
@@ -187,6 +187,12 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
                         brq.cmd.opcode = MMC_WRITE_BLOCK;
                         brq.data.flags |= MMC_DATA_WRITE;
                         brq.data.blocks = 1;
+
+                        /*
+                         * Scale up the timeout by the r2w factor
+                         */
+                        brq.data.timeout_ns <<= card->csd.r2w_factor;
+                        brq.data.timeout_clks <<= card->csd.r2w_factor;
                 }
 
                 if (brq.data.blocks > 1) {