[PATCH 50/51] ARM: 7797/1: mmc: Use dma_max_pfn(dev) helper for bounce_limit calculations

Russell King rmk+kernel at arm.linux.org.uk
Thu Sep 19 16:43:07 PDT 2013

From: Santosh Shilimkar <santosh.shilimkar at ti.com>

DMA bounce limit is the maximum direct DMA'able memory beyond which
bounce buffers has to be used to perform dma operations. MMC queue layr
relies on dma_mask but its calculation is based on max_*pfn which
don't have uniform meaning across architectures. So make use of
dma_max_pfn() which is expected to return the DMAable maximum pfn
value across architectures.

Signed-off-by: Santosh Shilimkar <santosh.shilimkar at ti.com>
Signed-off-by: Russell King <rmk+kernel at arm.linux.org.uk>
 drivers/mmc/card/queue.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index fa9632e..357bbc5 100644
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -15,6 +15,7 @@
 #include <linux/freezer.h>
 #include <linux/kthread.h>
 #include <linux/scatterlist.h>
+#include <linux/dma-mapping.h>
 #include <linux/mmc/card.h>
 #include <linux/mmc/host.h>
@@ -196,7 +197,7 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 	struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 	if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
-		limit = *mmc_dev(host)->dma_mask;
+		limit = dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
 	mq->card = card;
 	mq->queue = blk_init_queue(mmc_request_fn, lock);

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