Hi all, Even though 1MB is reserved for descriptor table in IDMAC, the dw_mmc host driver is allowed to receive only maximum 128KB block length in one request. This is caused by setting improper max_blk_count. It needs to be e adjusted so that descriptor table is used fully. It is found that the performance is improved with the increased the max_blk_count. In my case, there is 82%(6%) improvement in sequential write(read). Is there anybody who knows the reason about the old setting? Best regards, Seungwon Jeon. Signed-off-by: Seungwon Jeon <tgih.jun@xxxxxxxxxxx> --- drivers/mmc/host/dw_mmc.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index bf3c9b4..af2b901 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -1804,9 +1804,9 @@ static int __init dw_mci_init_slot(struct dw_mci *host, unsigned int id) #ifdef CONFIG_MMC_DW_IDMAC mmc->max_segs = host->ring_size; mmc->max_blk_size = 65536; - mmc->max_blk_count = host->ring_size; mmc->max_seg_size = 0x1000; - mmc->max_req_size = mmc->max_seg_size * mmc->max_blk_count; + mmc->max_req_size = mmc->max_seg_size * host->ring_size; + mmc->max_blk_count = mmc->max_req_size / 512; #else mmc->max_segs = 64; mmc->max_blk_size = 65536; /* BLKSIZ is 16 bits */ -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
