[U-Boot] [RESEND PATCH] sunxi: mmc: increase status register polling rate for data transfers
Tobias Doerffel
tobias.doerffel at ed-chemnitz.de
Fri Jul 8 12:40:14 CEST 2016
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 <tobias.doerffel at ed-chemnitz.de>
---
drivers/mmc/sunxi_mmc.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/sunxi_mmc.c b/drivers/mmc/sunxi_mmc.c
index ce2dc4a..36da3b3 100644
--- a/drivers/mmc/sunxi_mmc.c
+++ b/drivers/mmc/sunxi_mmc.c
@@ -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)
--
2.1.4
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