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Subject[PATCH v2] dmaengine: mv_xor_v2: Fix -Wshift-negative-value
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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>
---
drivers/dma/mv_xor_v2.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index fa5dab481203..e3850f04f676 100644
--- 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);
}

--
2.23.0.rc1.153.gdeed80330f-goog
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