mmc: Add .multi_io_quirk callback for multi I/O HW bug
Historically, we have been using MMC_CAP* to handle host HW issues and
currently the block layer uses MMC_CAP2_NO_MULTI_READ flag for a multi
I/O HW bug workaround.
There are a few tweaks needed to make MMC_CAP2_NO_MULTI_READ suite all
situations. Therefore let's add an optional host ops callback to enable
host drivers to return the number of blocks it allows per request.
In a future patch and when host drivers have converted to the new
callback, MMC_CAP2_NO_MULTI_READ shall be removed.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index ede41f0..adab903 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1402,6 +1402,16 @@
if (card->host->caps2 & MMC_CAP2_NO_MULTI_READ &&
rq_data_dir(req) == READ)
brq->data.blocks = 1;
+
+ /*
+ * Some controllers have HW issues while operating
+ * in multiple I/O mode
+ */
+ if (card->host->ops->multi_io_quirk)
+ brq->data.blocks = card->host->ops->multi_io_quirk(card,
+ (rq_data_dir(req) == READ) ?
+ MMC_DATA_READ : MMC_DATA_WRITE,
+ brq->data.blocks);
}
if (brq->data.blocks > 1 || do_rel_wr) {