[MMC] Fix SD timeout calculation

Secure Digital cards use a different algorithm to calculate the timeout
for data transfers. Using the MMC one works often, but not always.

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

2 files changed, 49 insertions, 10 deletions

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 33525bdf2ab6..c0c7ef2a8b28 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -912,6 +912,7 @@ static void mmc_read_scrs(struct mmc_host *host)
         struct mmc_request mrq;
         struct mmc_command cmd;
         struct mmc_data data;
+        unsigned int timeout_us;
 
         struct scatterlist sg;
 
@@ -947,8 +948,18 @@ static void mmc_read_scrs(struct mmc_host *host)
 
                 memset(&data, 0, sizeof(struct mmc_data));
 
-                data.timeout_ns = card->csd.tacc_ns * 10;
-                data.timeout_clks = card->csd.tacc_clks * 10;
+                data.timeout_ns = card->csd.tacc_ns * 100;
+                data.timeout_clks = card->csd.tacc_clks * 100;
+
+                timeout_us = data.timeout_ns / 1000;
+                timeout_us += data.timeout_clks * 1000 /
+                        (host->ios.clock / 1000);
+
+                if (timeout_us > 100000) {
+                        data.timeout_ns = 100000000;
+                        data.timeout_clks = 0;
+                }
+
                 data.blksz_bits = 3;
                 data.blksz = 1 << 3;
                 data.blocks = 1;
diff --git a/drivers/mmc/mmc_block.c b/drivers/mmc/mmc_block.c
index 115cc21094b9..515fb227eba7 100644
--- a/drivers/mmc/mmc_block.c
+++ b/drivers/mmc/mmc_block.c
@@ -30,6 +30,7 @@
 #include <linux/mutex.h>
 
 #include <linux/mmc/card.h>
+#include <linux/mmc/host.h>
 #include <linux/mmc/protocol.h>
 
 #include <asm/system.h>
@@ -171,8 +172,6 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
 
                 brq.cmd.arg = req->sector << 9;
                 brq.cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
-                brq.data.timeout_ns = card->csd.tacc_ns * 10;
-                brq.data.timeout_clks = card->csd.tacc_clks * 10;
                 brq.data.blksz_bits = md->block_bits;
                 brq.data.blksz = 1 << md->block_bits;
                 brq.data.blocks = req->nr_sectors >> (md->block_bits - 9);
@@ -180,6 +179,41 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
                 brq.stop.arg = 0;
                 brq.stop.flags = MMC_RSP_R1B | MMC_CMD_AC;
 
+                brq.data.timeout_ns = card->csd.tacc_ns * 10;
+                brq.data.timeout_clks = card->csd.tacc_clks * 10;
+
+                /*
+                 * Scale up the timeout by the r2w factor
+                 */
+                if (rq_data_dir(req) == WRITE) {
+                        brq.data.timeout_ns <<= card->csd.r2w_factor;
+                        brq.data.timeout_clks <<= card->csd.r2w_factor;
+                }
+
+                /*
+                 * SD cards use a 100 multiplier and has a upper limit
+                 */
+                if (mmc_card_sd(card)) {
+                        unsigned int limit_us, timeout_us;
+
+                        brq.data.timeout_ns *= 10;
+                        brq.data.timeout_clks *= 10;
+
+                        if (rq_data_dir(req) == READ)
+                                limit_us = 100000;
+                        else
+                                limit_us = 250000;
+
+                        timeout_us = brq.data.timeout_ns / 1000;
+                        timeout_us += brq.data.timeout_clks * 1000 /
+                                (card->host->ios.clock / 1000);
+
+                        if (timeout_us > limit_us) {
+                                brq.data.timeout_ns = limit_us * 1000;
+                                brq.data.timeout_clks = 0;
+                        }
+                }
+
                 if (rq_data_dir(req) == READ) {
                         brq.cmd.opcode = brq.data.blocks > 1 ? MMC_READ_MULTIPLE_BLOCK : MMC_READ_SINGLE_BLOCK;
                         brq.data.flags |= MMC_DATA_READ;
@@ -187,12 +221,6 @@ 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) {