Blackfin Serial Driver: Fix bug - request UART2/3 peripheral mapped interrupts in PIO mode

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 7 deletions

diff --git a/arch/blackfin/kernel/bfin_dma_5xx.c b/arch/blackfin/kernel/bfin_dma_5xx.c
index 93229b3d6e3e..339293d677cc 100644
--- a/arch/blackfin/kernel/bfin_dma_5xx.c
+++ b/arch/blackfin/kernel/bfin_dma_5xx.c
@@ -117,15 +117,14 @@ int request_dma(unsigned int channel, char *device_id)
 
 #ifdef CONFIG_BF54x
         if (channel >= CH_UART2_RX && channel <= CH_UART3_TX) {
-                if (strncmp(device_id, "BFIN_UART", 9) == 0) {
-                        dma_ch[channel].regs->peripheral_map &= 0x0FFF;
-                        dma_ch[channel].regs->peripheral_map |=
+                unsigned int per_map;
+                per_map = dma_ch[channel].regs->peripheral_map & 0xFFF;
+                if (strncmp(device_id, "BFIN_UART", 9) == 0)
+                        dma_ch[channel].regs->peripheral_map = per_map |
                                 ((channel - CH_UART2_RX + 0xC)<<12);
-                } else {
-                        dma_ch[channel].regs->peripheral_map &= 0x0FFF;
-                        dma_ch[channel].regs->peripheral_map |=
+                else
+                        dma_ch[channel].regs->peripheral_map = per_map |
                                 ((channel - CH_UART2_RX + 0x6)<<12);
-                }
         }
 #endif