[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>

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index da6ddd9..05aa4d6 100644 (file)
--- 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 8eb2a2e..06bd1f4 100644 (file)
--- 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) {

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 30dd978..991a373 100644 (file)
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -28,6 +28,7 @@ struct mmc_csd {
        unsigned short          cmdclass;
        unsigned short          tacc_clks;
        unsigned int            tacc_ns;
+       unsigned int            r2w_factor;
        unsigned int            max_dtr;
        unsigned int            read_blkbits;
        unsigned int            write_blkbits;