mmc: mxcmmc: fix falling back to PIO

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: <stable@kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c
index 325ea61..8e0fbe9 100644 (file)
--- a/drivers/mmc/host/mxcmmc.c
+++ b/drivers/mmc/host/mxcmmc.c
@@ -732,6 +732,7 @@ 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;
                }
        }