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. Tested by several people with no side-effects found. Signed-off-by: Pierre Ossman <[EMAIL PROTECTED]> --- Previously submitted: 2005-03-16 Previously submitted: 2004-12-03
Index: linux-wbsd/drivers/mmc/mmc_block.c =================================================================== --- linux-wbsd/drivers/mmc/mmc_block.c (revision 77) +++ linux-wbsd/drivers/mmc/mmc_block.c (working copy) @@ -166,9 +166,25 @@ struct mmc_blk_data *md = mq->data; 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; @@ -189,14 +205,32 @@ 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; @@ -204,19 +238,19 @@ 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 { @@ -229,7 +263,7 @@ 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)); @@ -255,6 +289,27 @@ 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); Index: linux-wbsd/drivers/mmc/Kconfig =================================================================== --- linux-wbsd/drivers/mmc/Kconfig (revision 96) +++ linux-wbsd/drivers/mmc/Kconfig (working copy) @@ -41,6 +41,15 @@ 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