diff options
author | Pierre Ossman <drzeus@drzeus.cx> | 2008-07-05 23:10:27 (GMT) |
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committer | Pierre Ossman <drzeus@drzeus.cx> | 2008-07-15 12:14:49 (GMT) |
commit | 23af60398af2f5033e2f53665538a09f498dbc03 (patch) | |
tree | fc244139d7d6bb1a82b80cc60fae86970e60c8c5 /drivers/mmc/card/block.c | |
parent | 97067d5581ec831a75a45a52e417bee0f7943dbf (diff) | |
download | linux-fsl-qoriq-23af60398af2f5033e2f53665538a09f498dbc03.tar.xz |
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 <drzeus@drzeus.cx>
Diffstat (limited to 'drivers/mmc/card/block.c')
-rw-r--r-- | drivers/mmc/card/block.c | 47 |
1 files changed, 19 insertions, 28 deletions
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 4b0f822..66e5a54 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); |