[U-Boot] [PATCH] dfu:mmc: When doing block operations, operate on the given length

[Tom Rini]

When working on RAW partitions, it's possible that the whole area
is larger than DDR.  So what we need to do is make sure that the length
we are given is aligned with the LBA block size, then pass that length
in as our count of LBA blocks to operate on.  In doing this, we no
longer need to modify *len on read operations.

Cc: Lukasz Majewski <l.majewski at samsung.com>
Signed-off-by: Tom Rini <trini at ti.com>
---
 drivers/dfu/dfu_mmc.c |   21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/dfu/dfu_mmc.c b/drivers/dfu/dfu_mmc.c
index 083d745..0bed405 100644
--- a/drivers/dfu/dfu_mmc.c
+++ b/drivers/dfu/dfu_mmc.c
@@ -34,14 +34,21 @@ static int mmc_block_op(enum dfu_mmc_op op, struct dfu_entity *dfu,
 {
 	char cmd_buf[DFU_CMD_BUF_SIZE];
 
-	sprintf(cmd_buf, "mmc %s 0x%x %x %x",
-		op == DFU_OP_READ ? "read" : "write",
-		(unsigned int) buf,
-		dfu->data.mmc.lba_start,
-		dfu->data.mmc.lba_size);
+	/*
+	 * We must ensure that we read in lba_blk_size chunks, so ALIGN
+	 * this value.
+	 */
+	*len = ALIGN(*len, dfu->data.mmc.lba_blk_size);
+
+	if (*len > (dfu->data.mmc.lba_size * dfu->data.mmc.lba_blk_size)) {
+		puts("Request would exceed designated area!\n");
+		return -EINVAL;
+	}
 
-	if (op == DFU_OP_READ)
-		*len = dfu->data.mmc.lba_blk_size * dfu->data.mmc.lba_size;
+	sprintf(cmd_buf, "mmc %s 0x%x %x %lx",
+		op == DFU_OP_READ ? "read" : "write",
+		(unsigned int) buf, dfu->data.mmc.lba_start,
+		*len / dfu->data.mmc.lba_blk_size);
 
 	debug("%s: %s 0x%p\n", __func__, cmd_buf, cmd_buf);
 	return run_command(cmd_buf, 0);
-- 
1.7.9.5