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mmc_spi: speedup for slow cards, less wear-out

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Speedup for slow cards by transfering more data at once.
This patch also reduces the amount of wear-out of the flash
blocks because fewer partial blocks are written.

Signed-off-by: Wolfgang Muees <wolfgang.mues@auerswald.de>
Signed-off-by: Pierre Ossman <pierre@ossman.eu>
This commit is contained in:
Wolfgang Muees 2009-04-08 10:14:07 +01:00 committed by Pierre Ossman
parent 94d89efb2c
commit 5cf20aa557
1 changed files with 12 additions and 0 deletions
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12
drivers/mmc/host/mmc_spi.c
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@ -97,6 +97,14 @@
*/
#define r1b_timeout (HZ * 3)
/* One of the critical speed parameters is the amount of data which may
* be transfered in one command. If this value is too low, the SD card
* controller has to do multiple partial block writes (argggh!). With
* today (2008) SD cards there is little speed gain if we transfer more
* than 64 KBytes at a time. So use this value until there is any indication
* that we should do more here.
*/
#define MMC_SPI_BLOCKSATONCE 128
/****************************************************************************/
@ -1366,6 +1374,10 @@ static int mmc_spi_probe(struct spi_device *spi)
mmc->ops = &mmc_spi_ops;
mmc->max_blk_size = MMC_SPI_BLOCKSIZE;
mmc->max_hw_segs = MMC_SPI_BLOCKSATONCE;
mmc->max_phys_segs = MMC_SPI_BLOCKSATONCE;
mmc->max_req_size = MMC_SPI_BLOCKSATONCE * MMC_SPI_BLOCKSIZE;
mmc->max_blk_count = MMC_SPI_BLOCKSATONCE;
mmc->caps = MMC_CAP_SPI;