[PATCH v3 1/3] mmc: dw_mmc: fix the max_blk_count in IDMAC
From: dianders@chromium.org (Doug Anderson)
Date: 2015-01-02 23:07:20
Also in:
linux-mmc
Alim, On Mon, Dec 22, 2014 at 4:12 AM, Alim Akhtar [off-list ref] wrote:
quoted hunk ↗ jump to hunk
From: Seungwon Jeon <redacted> 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. Signed-off-by: Seungwon Jeon <redacted> Acked-by: Jaehoon Chung <jh80.chung@samsung.com> Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com> --- drivers/mmc/host/dw_mmc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 64ea042..a1b80e5 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c@@ -2332,9 +2332,9 @@ static int 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;
The numbers are a little different than the ones you and Sonny arrived at about a year ago at <https://chromium-review.googlesource.com/#/c/176488/> You end up with the same max_req_size I think, but it looks as if max_blk_count is 0x800 in your series and ix 0xffff in the one from a year ago. Do you have any explanation for why it is max_req_size / 512? -Doug