sunxi: mmc: increase status register polling rate for data transfers
Subsystems (2)
PATCH 1/1 sunxi: mmc: increase status register polling rate for data transfers
With a recent bunch of SD3.0 cards in our A20-based board we experienced data transfer rates of about 250 KiB/s instead of 10 MiB/s with previous cards from the same vendor (both 4 GB/class 10). By increasing status register polling rate from 1 kHz to 1 MHz we were able to reach the original transfer rates again. With the old cards we now even reach about 16 MiB/s.
--- drivers/mmc/sunxi_mmc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
drivers/mmc/sunxi_mmc.c +5 -5
@@ -269,18 +269,18 @@ static int mmc_trans_data_by_cpu(struct mmc *mmc, struct mmc_data *data)unsigned i;unsigned *buff = (unsigned int *)(reading ? data->dest : data->src);unsigned byte_cnt = data->blocksize * data->blocks; -unsigned timeout_msecs = byte_cnt >>8 ; -if (timeout_msecs <2000 ) - timeout_msecs =2000 ; +unsigned timeout_usecs = ( byte_cnt >>8 ) *1000 ; +if (timeout_usecs <2000000 ) + timeout_usecs =2000000 ;/* Always read / write data through the CPU */ setbits_le32 (&mmchost->reg->gctrl,SUNXI_MMC_GCTRL_ACCESS_BY_AHB );for (i =0 ; i < (byte_cnt >>2 ); i++) {while (readl (&mmchost->reg->status) & status_bit) { -if (!timeout_msecs--) +if (!timeout_usecs--)return -1 ; -udelay (1000 ); +udelay (1 ); }if (reading)
Signature · 1 line
2.1.4
PATCH 1/1 sunxi: mmc: increase status register polling rate for data transfers
Hi Tobias,
Quoted 17 lines · Tobias Doerffel
With a recent bunch of SD3.0 cards in our A20-based board we experienced data transfer rates of about 250 KiB/s instead of 10 MiB/s with previous cards from the same vendor (both 4 GB/class 10). By increasing status register polling rate from 1 kHz to 1 MHz we were able to reach the original transfer rates again. With the old cards we now even reach about 16 MiB/s.
Signed-off-by Tobias Doerffel <[email protected]>--- drivers/mmc/sunxi_mmc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)drivers/mmc/sunxi_mmc.c +0
-0
drivers/mmc/sunxi_mmc.c static int mmc_trans_data_by_cpu(struct mmc *mmc, struct mmc_data *data) · line 272
Quoted 7 lines
drivers/mmc/sunxi_mmc.c +1
-3@@ -269,18 +269,18 @@ static int mmc_trans_data_by_cpu(struct mmc *mmc, struct mmc_data *data)unsigned i;unsigned *buff = (unsigned int *)(reading ? data->dest : data->src);unsigned byte_cnt = data->blocksize * data->blocks; -unsigned timeout_msecs = byte_cnt >>8 ; -if (timeout_msecs <2000 ) - timeout_msecs =2000 ; +unsigned timeout_usecs = ( byte_cnt >>8 ) *1000 ;
ERROR: space prohibited after that open parenthesis '(' #31: FILE: drivers/mmc/sunxi_mmc.c:272:
+ unsigned timeout_usecs = ( byte_cnt >> 8 ) * 1000;
ERROR: space prohibited before that close parenthesis ')' #31: FILE: drivers/mmc/sunxi_mmc.c:272:
+ unsigned timeout_usecs = ( byte_cnt >> 8 ) * 1000;
Best Regards,
Jaehoon Chung
Quoted 17 lines
drivers/mmc/sunxi_mmc.c +4
-2+if (timeout_usecs <2000000 ) + timeout_usecs =2000000 ;/* Always read / write data through the CPU */ setbits_le32 (&mmchost->reg->gctrl,SUNXI_MMC_GCTRL_ACCESS_BY_AHB );for (i =0 ; i < (byte_cnt >>2 ); i++) {while (readl (&mmchost->reg->status) & status_bit) { -if (!timeout_msecs--) +if (!timeout_usecs--)return -1 ; -udelay (1000 ); +udelay (1 ); }if (reading)