lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

mmc: remove multiwrite capability

Browse Source 
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>
This commit is contained in:
Pierre Ossman
2008-07-06 01:10:27 +02:00
parent 97067d5581
commit 23af60398a
9 changed files with 29 additions and 43 deletions
Download Patch File Download Diff File Expand all files Collapse all files

45
drivers/mmc/card/block.c
View File

@@ -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;
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;
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);