sdio: clean up handling of byte mode transfer size

Make sure that the maximum size for a byte mode transfer is identical
in all places. Also tweak the transfer helper so that a single byte
mode transfer is preferred over (possibly multiple) block mode
request(s).

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index 6ee7861..cc42a41 100644 (file)
--- a/drivers/mmc/core/sdio_io.c
+++ b/drivers/mmc/core/sdio_io.c
@@ -186,9 +186,20 @@ int sdio_set_block_size(struct sdio_func *func, unsigned blksz)
        func->cur_blksize = blksz;
        return 0;
 }
-
 EXPORT_SYMBOL_GPL(sdio_set_block_size);
 
+/*
+ * Calculate the maximum byte mode transfer size
+ */
+static inline unsigned int sdio_max_byte_size(struct sdio_func *func)
+{
+       return min(min(min(
+               func->card->host->max_seg_size,
+               func->card->host->max_blk_size),
+               func->max_blksize),
+               512u); /* maximum size for byte mode */
+}
+
 /**
  *     sdio_align_size - pads a transfer size to a more optimal value
  *     @func: SDIO function
@@ -222,7 +233,7 @@ unsigned int sdio_align_size(struct sdio_func *func, unsigned int sz)
         * If we can still do this with just a byte transfer, then
         * we're done.
         */
-       if ((sz <= func->cur_blksize) && (sz <= 512))
+       if (sz <= sdio_max_byte_size(func))
                return sz;
 
        if (func->card->cccr.multi_block) {
@@ -253,7 +264,7 @@ unsigned int sdio_align_size(struct sdio_func *func, unsigned int sz)
                 */
                byte_sz = mmc_align_data_size(func->card,
                                sz % func->cur_blksize);
-               if ((byte_sz <= func->cur_blksize) && (byte_sz <= 512)) {
+               if (byte_sz <= sdio_max_byte_size(func)) {
                        blk_sz = sz / func->cur_blksize;
                        return blk_sz * func->cur_blksize + byte_sz;
                }
@@ -263,8 +274,8 @@ unsigned int sdio_align_size(struct sdio_func *func, unsigned int sz)
                 * controller can handle the chunk size;
                 */
                chunk_sz = mmc_align_data_size(func->card,
-                               min(func->cur_blksize, 512u));
-               if (chunk_sz == min(func->cur_blksize, 512u)) {
+                               sdio_max_byte_size(func));
+               if (chunk_sz == sdio_max_byte_size(func)) {
                        /*
                         * Fix up the size of the remainder (if any)
                         */
@@ -296,7 +307,7 @@ static int sdio_io_rw_ext_helper(struct sdio_func *func, int write,
        int ret;
 
        /* Do the bulk of the transfer using block mode (if supported). */
-       if (func->card->cccr.multi_block) {
+       if (func->card->cccr.multi_block && (size > sdio_max_byte_size(func))) {
                /* Blocks per command is limited by host count, host transfer
                 * size (we only use a single sg entry) and the maximum for
                 * IO_RW_EXTENDED of 511 blocks. */
@@ -328,11 +339,7 @@ static int sdio_io_rw_ext_helper(struct sdio_func *func, int write,
 
        /* Write the remainder using byte mode. */
        while (remainder > 0) {
-               size = remainder;
-               if (size > func->cur_blksize)
-                       size = func->cur_blksize;
-               if (size > 512)
-                       size = 512; /* maximum size for byte mode */
+               size = min(remainder, sdio_max_byte_size(func));
 
                ret = mmc_io_rw_extended(func->card, write, func->num, addr,
                         incr_addr, buf, 1, size);