From: Pierre Ossman Adds support for writing multiple sectors at once. This allows back-to-back transfers of sectors giving roughly double write throughput. To be able to detect which sector is causing problems the system falls back to single sector writes if a failure is detected. Signed-off-by: Pierre Ossman Cc: Russell King Signed-off-by: Andrew Morton --- drivers/mmc/Kconfig | 9 ++++++ drivers/mmc/mmc_block.c | 67 +++++++++++++++++++++++++++++++++++++++++++----- 2 files changed, 70 insertions(+), 6 deletions(-) diff -puN drivers/mmc/Kconfig~mmc-multi-sector-writes drivers/mmc/Kconfig --- 25/drivers/mmc/Kconfig~mmc-multi-sector-writes Wed Aug 17 15:52:31 2005 +++ 25-akpm/drivers/mmc/Kconfig Wed Aug 17 15:52:31 2005 @@ -29,6 +29,15 @@ config MMC_BLOCK mount the filesystem. Almost everyone wishing MMC support should say Y or M here. +config MMC_BULKTRANSFER + bool "Multi-block writes (EXPERIMENTAL)" + depends on MMC_BLOCK != n && EXPERIMENTAL + default n + help + By default all writes are done one sector at a time. Enable + this option to transfer as large blocks as the host supports. + The transfer speed is in most cases doubled. + config MMC_ARMMMCI tristate "ARM AMBA Multimedia Card Interface support" depends on ARM_AMBA && MMC diff -puN drivers/mmc/mmc_block.c~mmc-multi-sector-writes drivers/mmc/mmc_block.c --- 25/drivers/mmc/mmc_block.c~mmc-multi-sector-writes Wed Aug 17 15:52:31 2005 +++ 25-akpm/drivers/mmc/mmc_block.c Wed Aug 17 15:52:31 2005 @@ -171,9 +171,25 @@ static int mmc_blk_issue_rq(struct mmc_q struct mmc_card *card = md->queue.card; int ret; +#ifdef CONFIG_MMC_BULKTRANSFER + int failsafe; +#endif + if (mmc_card_claim_host(card)) goto cmd_err; +#ifdef CONFIG_MMC_BULKTRANSFER + /* + * We first try transfering multiple blocks. If this fails + * we fall back to single block transfers. + * + * This gives us good performance when all is well and the + * possibility to determine which sector fails when all + * is not well. + */ + failsafe = 0; +#endif + do { struct mmc_blk_request brq; struct mmc_command cmd; @@ -192,14 +208,32 @@ static int mmc_blk_issue_rq(struct mmc_q brq.stop.arg = 0; brq.stop.flags = MMC_RSP_R1B; +#ifdef CONFIG_MMC_BULKTRANSFER + /* + * A multi-block transfer failed. Falling back to single + * blocks. + */ + if (failsafe) + brq.data.blocks = 1; + +#else + /* + * Writes are done one sector at a time. + */ + if (rq_data_dir(req) != READ) + brq.data.blocks = 1; +#endif + + ret = 1; + 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; } else { - brq.cmd.opcode = MMC_WRITE_BLOCK; + brq.cmd.opcode = brq.data.blocks > 1 ? MMC_WRITE_MULTIPLE_BLOCK : + MMC_WRITE_BLOCK; brq.cmd.flags = MMC_RSP_R1B; brq.data.flags |= MMC_DATA_WRITE; - brq.data.blocks = 1; } brq.mrq.stop = brq.data.blocks > 1 ? &brq.stop : NULL; @@ -210,19 +244,19 @@ static int mmc_blk_issue_rq(struct mmc_q if (brq.cmd.error) { printk(KERN_ERR "%s: error %d sending read/write command\n", req->rq_disk->disk_name, brq.cmd.error); - goto cmd_err; + goto cmd_fail; } if (brq.data.error) { printk(KERN_ERR "%s: error %d transferring data\n", req->rq_disk->disk_name, brq.data.error); - goto cmd_err; + goto cmd_fail; } if (brq.stop.error) { printk(KERN_ERR "%s: error %d sending stop command\n", req->rq_disk->disk_name, brq.stop.error); - goto cmd_err; + goto cmd_fail; } do { @@ -235,7 +269,7 @@ static int mmc_blk_issue_rq(struct mmc_q if (err) { printk(KERN_ERR "%s: error %d requesting status\n", req->rq_disk->disk_name, err); - goto cmd_err; + goto cmd_fail; } } while (!(cmd.resp[0] & R1_READY_FOR_DATA)); @@ -261,6 +295,27 @@ static int mmc_blk_issue_rq(struct mmc_q end_that_request_last(req); } spin_unlock_irq(&md->lock); + +#ifdef CONFIG_MMC_BULKTRANSFER + /* + * Go back to bulk mode if in failsafe mode. + */ + failsafe = 0; +#endif + + continue; + + cmd_fail: + +#ifdef CONFIG_MMC_BULKTRANSFER + if (failsafe) + goto cmd_err; + else + failsafe = 1; +#else + goto cmd_err; +#endif + } while (ret); mmc_card_release_host(card); _