From: Nathan Huckleberry <nhuck@google.com>
To: dan.j.williams@intel.com, vkoul@kernel.org
Cc: dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
Nathan Huckleberry <nhuck@google.com>,
clang-built-linux@googlegroups.com
Subject: [PATCH] dmaengine: mv_xor_v2: Fix -Wshift-negative-value
Date: Wed, 12 Jun 2019 15:54:19 -0700 [thread overview]
Message-ID: <20190612225419.241618-1-nhuck@google.com> (raw)
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..5d2e0d1f3ec9 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);
}
--
2.22.0.rc2.383.gf4fbbf30c2-goog
next reply other threads:[~2019-06-13 17:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 22:54 Nathan Huckleberry [this message]
2019-06-12 23:14 ` [PATCH] dmaengine: mv_xor_v2: Fix -Wshift-negative-value Nick Desaulniers
2019-08-13 17:34 ` [PATCH v2] " Nathan Huckleberry
2019-08-13 20:43 ` Nick Desaulniers
2019-08-20 11:36 ` Vinod Koul
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