tree 14c2872048dde7e15d386f1211836c86b1b6c69f
parent e0bc6ff8b8d5c066d978d23e690d5599db4cb2b3
author Guennadi Liakhovetski <g.liakhovetski@gmx.de> 1293015735 +0100
committer Chris Ball <cjb@laptop.org> 1294548749 -0500

mmc: tmio_mmc: implement a bounce buffer for unaligned DMA

For example, with SDIO WLAN cards, some transfers happen with buffers at
odd addresses, whereas the SH-Mobile DMA engine requires even addresses
for SDHI. This patch extends the tmio driver with a bounce buffer, that
is used for single entry scatter-gather lists both for sending and
receiving. If we ever encounter unaligned transfers with multi-element
sg lists, this patch will have to be extended. For now it just falls
back to PIO in this and other unsupported cases.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>