linux_dsm_epyc7002/drivers/mmc
Daniel Drake 5ea47691bd mmc: alcor: fix DMA reads
Setting max_blk_count to 1 here was causing the mmc block layer
to always use the MMC_READ_SINGLE_BLOCK command here, which the
driver does not DMA-accelerate.

Drop the max_blk_ settings here. The mmc host defaults suffice,
along with the max_segs and max_seg_size settings, which I have
now documented in more detail.

Now each MMC command reads 4 512-byte blocks, using DMA instead of
PIO. On my SD card, this increases read performance (measured with dd)
from 167kb/sec to 4.6mb/sec.

Link: http://lkml.kernel.org/r/CAD8Lp47L5T3jnAjBiPs1cQ+yFA3L6LJtgFvMETnBrY63-Zdi2g@mail.gmail.com
Signed-off-by: Daniel Drake <drake@endlessm.com>
Reviewed-by: Oleksij Rempel <linux@rempel-privat.de>
Fixes: c5413ad815 ("mmc: add new Alcor Micro Cardreader SD/MMC driver")
Cc: stable@vger.kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2019-03-21 11:19:06 +01:00
..
core for-5.1/block-20190302 2019-03-08 14:12:17 -08:00
host mmc: alcor: fix DMA reads 2019-03-21 11:19:06 +01:00
Kconfig mmc: core: Remove option not to use blk-mq 2017-12-11 12:55:02 +01:00
Makefile mmc: Kconfig: downgrade CONFIG_MMC_DEBUG for host drivers only 2017-08-30 14:01:34 +02:00