[U-Boot] [PATCH] mmc: seperate block number into small parts for multi-write cmd

[Lei Wen]

As mmc host limitation, the max number of block in one go
should be limited to 65535, and the max buffer size should
not excceed 512k bytes.

Signed-off-by: Lei Wen <leiwen at marvell.com>
---
 drivers/mmc/mmc.c |   56 +++++++++++++++++++++++++++++++++-------------------
 1 files changed, 35 insertions(+), 21 deletions(-)

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 94d1ac2..ea398a5 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -77,29 +77,16 @@ struct mmc *find_mmc_device(int dev_num)
 	return NULL;
 }
 
-static ulong
-mmc_bwrite(int dev_num, ulong start, lbaint_t blkcnt, const void*src)
+int mmc_write_block(struct mmc *mmc, ulong *src, ulong start, uint blocknum)
 {
 	struct mmc_cmd cmd;
 	struct mmc_data data;
-	int err;
-	int stoperr = 0;
-	struct mmc *mmc = find_mmc_device(dev_num);
-	int blklen;
-
-	if (!mmc)
-		return -1;
-
+	int blklen, err;
 	blklen = mmc->write_bl_len;
 
-	err = mmc_set_blocklen(mmc, mmc->write_bl_len);
-
-	if (err) {
-		printf("set write bl len failed\n\r");
-		return err;
-	}
-
-	if (blkcnt > 1)
+	BUG_ON(blklen * blocknum > 524288);
+	BUG_ON(blocknum > 65535);
+	if (blocknum > 1)
 		cmd.cmdidx = MMC_CMD_WRITE_MULTIPLE_BLOCK;
 	else
 		cmd.cmdidx = MMC_CMD_WRITE_SINGLE_BLOCK;
@@ -113,7 +100,7 @@ mmc_bwrite(int dev_num, ulong start, lbaint_t blkcnt, const void*src)
 	cmd.flags = 0;
 
 	data.src = src;
-	data.blocks = blkcnt;
+	data.blocks = blocknum;
 	data.blocksize = blklen;
 	data.flags = MMC_DATA_WRITE;
 
@@ -124,14 +111,41 @@ mmc_bwrite(int dev_num, ulong start, lbaint_t blkcnt, const void*src)
 		return err;
 	}
 
-	if (blkcnt > 1) {
+	if (blocknum > 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);
+		mmc_send_cmd(mmc, &cmd, NULL);
 	}
 
+	return blocknum;
+}
+
+static ulong
+mmc_bwrite(int dev_num, ulong start, lbaint_t blkcnt, const void*src)
+{
+	int err;
+	struct mmc *mmc = find_mmc_device(dev_num);
+	unsigned int max;
+	lbaint_t tmp = blkcnt, cur;
+
+	if (!mmc)
+		return -1;
+
+	err = mmc_set_blocklen(mmc, mmc->write_bl_len);
+	if (err) {
+		printf("set write bl len failed\n\r");
+		return err;
+	}
+
+	max = 524288 / mmc->write_bl_len;
+	do {
+		cur = (tmp > max) ? max : tmp;
+		tmp -= cur;
+		if(mmc_write_block(mmc, src, start, cur) != cur)
+			return -1;
+	} while (tmp > 0);
 	return blkcnt;
 }
 
-- 
1.7.0.4