mmc,sdio: helper function for transfer padding

There are a lot of crappy controllers out there that cannot handle
all the request sizes that the MMC/SD/SDIO specifications require.
In case the card driver can pad the data to overcome the problems,
this commit adds a helper that calculates how much that padding
should be.

A corresponding helper is also added for SDIO, but it can also deal
with all the complexities of splitting up a large transfer efficiently.

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

1 files changed, 7 insertions, 13 deletions

diff --git a/drivers/net/wireless/libertas/if_sdio.c b/drivers/net/wireless/libertas/if_sdio.c
index 3dd537be87d8..b54e2ea8346b 100644
--- a/drivers/net/wireless/libertas/if_sdio.c
+++ b/drivers/net/wireless/libertas/if_sdio.c
@@ -1,7 +1,7 @@
 /*
  *  linux/drivers/net/wireless/libertas/if_sdio.c
  *
- *  Copyright 2007 Pierre Ossman
+ *  Copyright 2007-2008 Pierre Ossman
  *
  * Inspired by if_cs.c, Copyright 2007 Holger Schurig
  *
@@ -266,13 +266,10 @@ static int if_sdio_card_to_host(struct if_sdio_card *card)
 
         /*
          * The transfer must be in one transaction or the firmware
-         * goes suicidal.
+         * goes suicidal. There's no way to guarantee that for all
+         * controllers, but we can at least try.
          */
-        chunk = size;
-        if ((chunk > card->func->cur_blksize) || (chunk > 512)) {
-                chunk = (chunk + card->func->cur_blksize - 1) /
-                        card->func->cur_blksize * card->func->cur_blksize;
-        }
+        chunk = sdio_align_size(card->func, size);
 
         ret = sdio_readsb(card->func, card->buffer, card->ioport, chunk);
         if (ret)
@@ -696,13 +693,10 @@ static int if_sdio_host_to_card(struct lbs_private *priv,
 
         /*
          * The transfer must be in one transaction or the firmware
-         * goes suicidal.
+         * goes suicidal. There's no way to guarantee that for all
+         * controllers, but we can at least try.
          */
-        size = nb + 4;
-        if ((size > card->func->cur_blksize) || (size > 512)) {
-                size = (size + card->func->cur_blksize - 1) /
-                        card->func->cur_blksize * card->func->cur_blksize;
-        }
+        size = sdio_align_size(card->func, nb + 4);
 
         packet = kzalloc(sizeof(struct if_sdio_packet) + size,
                         GFP_ATOMIC);