mmc: sdio: Fix to support any block size optimally

This patch allows any block size to be set on the SDIO link,
and still have an arbitrary sized packet (adjusted in size by
using sdio_align_size) transferred in an optimal way
(preferably one transfer).

Previously if the block size was larger than the default of
512 bytes and the transfer size was exactly one block size
(possibly thanks to using sdio_align_size to get an optimal
transfer size), it was sent as a number of byte transfers instead
of one block transfer. Also if the number of blocks was
(max_blocks * N) + 1, the tranfer would be conducted with a number
of blocks and finished off with a number of byte transfers.

When doing this change it was also possible to break out the quirk
for broken byte mode in a much cleaner way, and collect the logic of
when to do byte or block transfer in one function instead of two.

ST-Ericsson ID: 368813
ST-Ericsson FOSS-OUT ID: Trivial
ST-Ericsson Linux next: TBD

Change-Id: I8afb00f37b70bf3e94743f732a1c7ff5f5b542bc
Signed-off-by: Stefan Nilsson XK <stefan.xk.nilsson@stericsson.com>
Reviewed-on: http://gerrit.lud.stericsson.com/gerrit/34578
Reviewed-by: Ulf HANSSON <ulf.hansson@stericsson.com>

2 files changed, 11 insertions, 11 deletions

diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index 549a3414464..aa1241c6066 100755
--- a/drivers/mmc/core/sdio_io.c
+++ b/drivers/mmc/core/sdio_io.c
@@ -195,6 +195,9 @@ static inline unsigned int sdio_max_byte_size(struct sdio_func *func)
 	else
 		mval = min(mval, func->max_blksize);
 
+	if (mmc_card_broken_byte_mode_512(func->card))
+		return min(mval, 511u);
+
 	return min(mval, 512u); /* maximum size for byte mode */
 }
 
@@ -313,7 +316,7 @@ static int sdio_io_rw_ext_helper(struct sdio_func *func, int write,
 			func->card->host->max_seg_size / func->cur_blksize);
 		max_blocks = min(max_blocks, 511u);
 
-		while (remainder > func->cur_blksize) {
+		while (remainder >= func->cur_blksize) {
 			unsigned blocks;
 
 			blocks = remainder / func->cur_blksize;
@@ -338,8 +341,9 @@ static int sdio_io_rw_ext_helper(struct sdio_func *func, int write,
 	while (remainder > 0) {
 		size = min(remainder, sdio_max_byte_size(func));
 
+		/* Indicate byte mode by setting "blocks" = 0 */
 		ret = mmc_io_rw_extended(func->card, write, func->num, addr,
-			 incr_addr, buf, 1, size);
+			 incr_addr, buf, 0, size);
 		if (ret)
 			return ret;
 
diff --git a/drivers/mmc/core/sdio_ops.c b/drivers/mmc/core/sdio_ops.c
index b0517cc0620..d29e20630ee 100644
--- a/drivers/mmc/core/sdio_ops.c
+++ b/drivers/mmc/core/sdio_ops.c
@@ -128,8 +128,6 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
 
 	BUG_ON(!card);
 	BUG_ON(fn > 7);
-	BUG_ON(blocks == 1 && blksz > 512);
-	WARN_ON(blocks == 0);
 	WARN_ON(blksz == 0);
 
 	/* sanity check */
@@ -144,22 +142,20 @@ int mmc_io_rw_extended(struct mmc_card *card, int write, unsigned fn,
 	cmd.arg |= fn << 28;
 	cmd.arg |= incr_addr ? 0x04000000 : 0x00000000;
 	cmd.arg |= addr << 9;
-	if (blocks == 1 && blksz < 512)
-		cmd.arg |= blksz;			/* byte mode */
-	else if (blocks == 1 && blksz == 512 &&
-		 !(mmc_card_broken_byte_mode_512(card)))
-		cmd.arg |= 0;				/* byte mode, 0==512 */
+	if (blocks == 0)
+		cmd.arg |= (blksz == 512) ? 0 : blksz;	/* byte mode */
 	else
 		cmd.arg |= 0x08000000 | blocks;		/* block mode */
 	cmd.flags = MMC_RSP_SPI_R5 | MMC_RSP_R5 | MMC_CMD_ADTC;
 
 	data.blksz = blksz;
-	data.blocks = blocks;
+	/* Code in host drivers/fwk assumes that "blocks" always is >=1 */
+	data.blocks = blocks ? blocks : 1;
 	data.flags = write ? MMC_DATA_WRITE : MMC_DATA_READ;
 	data.sg = &sg;
 	data.sg_len = 1;
 
-	sg_init_one(&sg, buf, blksz * blocks);
+	sg_init_one(&sg, buf, data.blksz * data.blocks);
 
 	mmc_set_data_timeout(&data, card);