Commit 698f7a9b authored by Nathan Huckleberry's avatar Nathan Huckleberry Committed by Vinod Koul
Browse files

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: default avatarNathan Huckleberry <nhuck@google.com>
Reviewed-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20190813173448.109859-1-nhuck@google.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 3a1144f8

drivers/dma/mv_xor_v2.c

+4 −7
Original line number Diff line number Diff line
@@ -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);

}