[PATCH] mmc mxcmmc: fix falling back to PIO

[s.hauer@pengutronix.de (Sascha Hauer)]

When we can't configure the dma channel we want to fall
back to PIO. We do this by setting host->do_dma to zero.
This does not work as do_dma is used to see whether dma
can be used for the current transfer. Instead, we have
to set host->dma to NULL.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Chris Ball <cjb@laptop.org>
Cc: linux-mmc at vger.kernel.org
---
 drivers/mmc/host/mxcmmc.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c
index 14aa213..b87143d 100644
--- a/drivers/mmc/host/mxcmmc.c
+++ b/drivers/mmc/host/mxcmmc.c
@@ -731,6 +731,7 @@ static void mxcmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 				"failed to config DMA channel. Falling back to PIO\n");
 			dma_release_channel(host->dma);
 			host->do_dma = 0;
+			host->dma = NULL;
 		}
 	}
 
-- 
1.7.7.1