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[MMC] Fix SD timeout calculation

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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>
This commit is contained in:
Pierre Ossman 2006-06-18 14:34:37 +02:00 committed by Russell King
parent f57b225e43
commit 385e3227d4
2 changed files with 49 additions and 10 deletions
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15
drivers/mmc/mmc.c
View File

@ -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;

44
drivers/mmc/mmc_block.c
View File

@ -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) {