dmaengine: mv_xor_v2: Fix -Wshift-negative-value

Clang produces the following warning

drivers/dma/mv_xor_v2.c:264:40: warning: shifting a negative signed value
	is undefined [-Wshift-negative-value]
        reg &= (~MV_XOR_V2_DMA_IMSG_THRD_MASK <<
	MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
drivers/dma/mv_xor_v2.c:271:46: warning: shifting a negative signed value
	is undefined [-Wshift-negative-value]
        reg &= (~MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK <<
                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^

Upon further investigation MV_XOR_V2_DMA_IMSG_THRD_SHIFT and
MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT are both 0. Since shifting by 0 does
nothing, these variables can be removed.

Cc: clang-built-linux@googlegroups.com
Link: https://github.com/ClangBuiltLinux/linux/issues/521
Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20190813173448.109859-1-nhuck@google.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index fa5dab481203ce36534b905f47f34aec0d443f82..e3850f04f6763fd81527eca39879e14d80cd70eb 100644 (file)
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -33,7 +33,6 @@
 #define MV_XOR_V2_DMA_IMSG_CDAT_OFF                    0x014
 #define MV_XOR_V2_DMA_IMSG_THRD_OFF                    0x018
 #define   MV_XOR_V2_DMA_IMSG_THRD_MASK                 0x7FFF
-#define   MV_XOR_V2_DMA_IMSG_THRD_SHIFT                        0x0
 #define   MV_XOR_V2_DMA_IMSG_TIMER_EN                  BIT(18)
 #define MV_XOR_V2_DMA_DESQ_AWATTR_OFF                  0x01C
   /* Same flags as MV_XOR_V2_DMA_DESQ_ARATTR_OFF */
@@ -50,7 +49,6 @@
 #define MV_XOR_V2_DMA_DESQ_ADD_OFF                     0x808
 #define MV_XOR_V2_DMA_IMSG_TMOT                                0x810
 #define   MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK           0x1FFF
-#define   MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT          0
 
 /* XOR Global registers */
 #define MV_XOR_V2_GLOB_BW_CTRL                         0x4
@@ -261,16 +259,15 @@ void mv_xor_v2_enable_imsg_thrd(struct mv_xor_v2_device *xor_dev)
 
        /* Configure threshold of number of descriptors, and enable timer */
        reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
-       reg &= (~MV_XOR_V2_DMA_IMSG_THRD_MASK << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
-       reg |= (MV_XOR_V2_DONE_IMSG_THRD << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
+       reg &= ~MV_XOR_V2_DMA_IMSG_THRD_MASK;
+       reg |= MV_XOR_V2_DONE_IMSG_THRD;
        reg |= MV_XOR_V2_DMA_IMSG_TIMER_EN;
        writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
 
        /* Configure Timer Threshold */
        reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
-       reg &= (~MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK <<
-               MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT);
-       reg |= (MV_XOR_V2_TIMER_THRD << MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT);
+       reg &= ~MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK;
+       reg |= MV_XOR_V2_TIMER_THRD;
        writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
 }