[U-Boot] [PATCH] Improve read performance of generic mmc.
Terry Lv
r65388 at freescale.com
Thu Nov 19 08:03:50 CET 2009
In drivers/mmc/mmc.c, mmc_bread will do aligned read.
So we don't need to use single block read.
We can use multiblock read to improve the performance.
Signed-off-by: Terry Lv <r65388 at freescale.com>
---
drivers/mmc/mmc.c | 51 ++++++++++++++++++++++++++++++++++++++++-----------
1 files changed, 40 insertions(+), 11 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index b69ce15..53ca3a1 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -205,27 +205,56 @@ free_buffer:
static ulong mmc_bread(int dev_num, ulong start, lbaint_t blkcnt, void *dst)
{
+ struct mmc_cmd cmd;
+ struct mmc_data data;
int err;
- int i;
+ int stoperr = 0;
struct mmc *mmc = find_mmc_device(dev_num);
+ int blklen;
if (!mmc)
- return 0;
+ return -1;
- /* We always do full block reads from the card */
- err = mmc_set_blocklen(mmc, mmc->read_bl_len);
+ blklen = mmc->read_bl_len;
+
+ err = mmc_set_blocklen(mmc, blklen);
if (err) {
- return 0;
+ printf("set read bl len failed\n\r");
+ return err;
}
- for (i = start; i < start + blkcnt; i++, dst += mmc->read_bl_len) {
- err = mmc_read_block(mmc, dst, i);
+ if (blkcnt > 1)
+ cmd.cmdidx = MMC_CMD_READ_MULTIPLE_BLOCK;
+ else
+ cmd.cmdidx = MMC_CMD_READ_SINGLE_BLOCK;
- if (err) {
- printf("block read failed: %d\n", err);
- return i - start;
- }
+ if (mmc->high_capacity)
+ cmd.cmdarg = start;
+ else
+ cmd.cmdarg = start * blklen;
+
+ cmd.resp_type = MMC_RSP_R1;
+ cmd.flags = 0;
+
+ data.dest = dst;
+ data.blocks = blkcnt;
+ data.blocksize = blklen;
+ data.flags = MMC_DATA_READ;
+
+ err = mmc_send_cmd(mmc, &cmd, &data);
+
+ if (err) {
+ printf("mmc read failed\n\r");
+ return err;
+ }
+
+ if (blkcnt > 1) {
+ cmd.cmdidx = MMC_CMD_STOP_TRANSMISSION;
+ cmd.cmdarg = 0;
+ cmd.resp_type = MMC_RSP_R1b;
+ cmd.flags = 0;
+ stoperr = mmc_send_cmd(mmc, &cmd, NULL);
}
return blkcnt;
--
1.6.0.4
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