From 23af60398af2f5033e2f53665538a09f498dbc03 Mon Sep 17 00:00:00 2001 From: Pierre Ossman Date: Sun, 6 Jul 2008 01:10:27 +0200 Subject: mmc: remove multiwrite capability Relax requirements on host controllers and only require that they do not report a transfer count than is larger than the actual one (i.e. a lower value is okay). This is how many other parts of the kernel behaves so upper layers should already be prepared to handle that scenario. This gives us a performance boost on MMC cards. Signed-off-by: Pierre Ossman --- drivers/mmc/card/block.c | 47 +++++++++++++++++++---------------------------- 1 file changed, 19 insertions(+), 28 deletions(-) (limited to 'drivers/mmc/card') diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 4b0f8220f153..66e5a5487c20 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -237,17 +237,6 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) if (brq.data.blocks > card->host->max_blk_count) brq.data.blocks = card->host->max_blk_count; - /* - * If the host doesn't support multiple block writes, force - * block writes to single block. SD cards are excepted from - * this rule as they support querying the number of - * successfully written sectors. - */ - if (rq_data_dir(req) != READ && - !(card->host->caps & MMC_CAP_MULTIWRITE) && - !mmc_card_sd(card)) - brq.data.blocks = 1; - if (brq.data.blocks > 1) { /* SPI multiblock writes terminate using a special * token, not a STOP_TRANSMISSION request. @@ -367,30 +356,32 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req) * mark the known good sectors as ok. * * If the card is not SD, we can still ok written sectors - * if the controller can do proper error reporting. + * as reported by the controller (which might be less than + * the real number of written sectors, but never more). * * For reads we just fail the entire chunk as that should * be safe in all cases. */ - if (rq_data_dir(req) != READ && mmc_card_sd(card)) { - u32 blocks; - unsigned int bytes; - - blocks = mmc_sd_num_wr_blocks(card); - if (blocks != (u32)-1) { - if (card->csd.write_partial) - bytes = blocks << md->block_bits; - else - bytes = blocks << 9; + if (rq_data_dir(req) != READ) { + if (mmc_card_sd(card)) { + u32 blocks; + unsigned int bytes; + + blocks = mmc_sd_num_wr_blocks(card); + if (blocks != (u32)-1) { + if (card->csd.write_partial) + bytes = blocks << md->block_bits; + else + bytes = blocks << 9; + spin_lock_irq(&md->lock); + ret = __blk_end_request(req, 0, bytes); + spin_unlock_irq(&md->lock); + } + } else { spin_lock_irq(&md->lock); - ret = __blk_end_request(req, 0, bytes); + ret = __blk_end_request(req, 0, brq.data.bytes_xfered); spin_unlock_irq(&md->lock); } - } else if (rq_data_dir(req) != READ && - (card->host->caps & MMC_CAP_MULTIWRITE)) { - spin_lock_irq(&md->lock); - ret = __blk_end_request(req, 0, brq.data.bytes_xfered); - spin_unlock_irq(&md->lock); } mmc_release_host(card->host); -- cgit v1.2.2