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 v2] dmaengine: mv_xor_v2: Fix -Wshift-negative-value
Date: Tue, 13 Aug 2019 10:34:48 -0700 [thread overview]
Message-ID: <20190813173448.109859-1-nhuck@google.com> (raw)
In-Reply-To: <CAKwvOdkAJcOCGvveBYaDD2kf4vx7m=b+Nxyn3_n=9aCBapzDcw@mail.gmail.com>
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
next prev parent reply other threads:[~2019-08-13 17:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-12 22:54 [PATCH] dmaengine: mv_xor_v2: Fix -Wshift-negative-value Nathan Huckleberry
2019-06-12 23:14 ` Nick Desaulniers
2019-08-13 17:34 ` Nathan Huckleberry [this message]
2019-08-13 20:43 ` [PATCH v2] " Nick Desaulniers
2019-08-20 11:36 ` Vinod Koul
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190813173448.109859-1-nhuck@google.com \
--to=nhuck@google.com \
--cc=clang-built-linux@googlegroups.com \
--cc=dan.j.williams@intel.com \
--cc=dmaengine@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=vkoul@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).