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.

Signed-off-by: Stefan Nilsson XK <stefan.xk.nilsson@stericsson.com>
Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index 0f687cdeb064ac917d778a35f9bc5c756f1da89e..b20fbb47b8251229dba52a4b08c74786e47508e7 100644 (file)
--- 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 b0517cc06200177d16766c84f237214a6f813d2f..d29e20630eed9249d339240d8e3ddd114d606a0a 100644 (file)
--- 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);