[MTD] [NAND] Blackfin NFC Driver: do not clobber DMAC1_PERIMUX

Only set DMAC1_PERIMUX once we have requested and been granted the dma
channel to prevent breaking other peripherals in the error case

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 6 insertions, 8 deletions

diff --git a/drivers/mtd/nand/bf5xx_nand.c b/drivers/mtd/nand/bf5xx_nand.c
index 9af2a2cc1153..5c6056e02426 100644
--- a/drivers/mtd/nand/bf5xx_nand.c
+++ b/drivers/mtd/nand/bf5xx_nand.c
@@ -552,7 +552,6 @@ static void bf5xx_nand_dma_write_buf(struct mtd_info *mtd,
 static int bf5xx_nand_dma_init(struct bf5xx_nand_info *info)
 {
         int ret;
-        unsigned short val;
 
         /* Do not use dma */
         if (!hardware_ecc)
@@ -560,13 +559,6 @@ static int bf5xx_nand_dma_init(struct bf5xx_nand_info *info)
 
         init_completion(&info->dma_completion);
 
-#ifdef CONFIG_BF54x
-        /* Setup DMAC1 channel mux for NFC which shared with SDH */
-        val = bfin_read_DMAC1_PERIMUX();
-        val &= 0xFFFE;
-        bfin_write_DMAC1_PERIMUX(val);
-        SSYNC();
-#endif
         /* Request NFC DMA channel */
         ret = request_dma(CH_NFC, "BF5XX NFC driver");
         if (ret < 0) {
@@ -574,6 +566,12 @@ static int bf5xx_nand_dma_init(struct bf5xx_nand_info *info)
                 return ret;
         }
 
+#ifdef CONFIG_BF54x
+        /* Setup DMAC1 channel mux for NFC which shared with SDH */
+        bfin_write_DMAC1_PERIMUX(bfin_read_DMAC1_PERIMUX() & ~1);
+        SSYNC();
+#endif
+
         set_dma_callback(CH_NFC, (void *) bf5xx_nand_dma_irq, (void *) info);
 
         /* Turn off the DMA channel first */