Hi, Did you know that Seungwon has sent the patch "[PATCH 1/7] mmc: dw_mmc: fix the max_blk_count in IDMAC"? I think this patch looks like same, isn't it? Plz check it. Best Regards, Jaehoon Chung On 03/24/2014 12:53 PM, Yuvaraj Kumar C D wrote: > From: Alim Akhtar <alim.akhtar@xxxxxxxxxxx> > > max_blk_count is currently set incorrectly, and the correct value can > be determined by looking at the maximum number of bytes which can be > transferred and the block size. We use the maximum block size to > determine the minimum number of blocks that the controller should > support. It could probably do more with a smaller block size but this > value should be sufficient for good performance. > > This improves sequential performance by 82% on write and 6% read on > one particular device. > > TEST= with this patch > time dd if=/dev/zero of=/usr/local/100 bs=1M count=100 conv=fdatasync > 100+0 records in > 100+0 records out > 104857600 bytes (105 MB) copied, 2.62541 s, 39.9 MB/s > > real 0m2.638s > user 0m0.000s > sys 0m0.645s > > without this patch: > time dd if=/dev/zero of=/usr/local/100 bs=1M count=100 conv=fdatasync > 100+0 records in > 100+0 records out > 104857600 bytes (105 MB) copied, 3.25873 s, 32.2 MB/s > > real 0m3.265s > user 0m0.005s > sys 0m0.690s > > Signed-off-by: Seungwon Jeon <tgih.jun@xxxxxxxxxxx> > Signed-off-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx> > Signed-off-by: Sonny Rao <sonnyrao@xxxxxxxxxxxx> > Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd@xxxxxxxxxxx> > --- > drivers/mmc/host/dw_mmc.c | 18 ++++++++++++++++-- > 1 file changed, 16 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index 0c56faa..2fc4030 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -2213,10 +2213,24 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id) > /* Useful defaults if platform data is unset. */ > #ifdef CONFIG_MMC_DW_IDMAC > mmc->max_segs = host->ring_size; > + > + /* the BLKSIZ register is 16-bits wide */ > mmc->max_blk_size = 65536; > - mmc->max_blk_count = host->ring_size; > + > + /* > + * This value is calculated by taking the size of the > + * 32-bit BYTCNT (byte count) register and dividing by the > + * BLKSIZ (block size) register. This is the minimum number > + * of blocks which could be handled. > + */ > + mmc->max_blk_count = 0xFFFF; > mmc->max_seg_size = 0x1000; > - mmc->max_req_size = mmc->max_seg_size * mmc->max_blk_count; > + /* > + * Maximum request size should be total number of descriptors > + * times the maximum amount of data each can reference > + */ > + > + mmc->max_req_size = mmc->max_seg_size * mmc->max_segs; > #else > mmc->max_segs = 64; > mmc->max_blk_size = 65536; /* BLKSIZ is 16 bits */ > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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