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From: Nathan Chancellor <nathan@kernel.org>
To: lizhi.hou@amd.com, brian.xu@amd.com, raj.kumar.rampelli@amd.com,
	 vkoul@kernel.org, jankul@alatek.krakow.pl
Cc: dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	 llvm@lists.linux.dev, patches@lists.linux.dev,
	 Nathan Chancellor <nathan@kernel.org>
Subject: [PATCH 2/2] dmaengine: xilinx: xdma: Fix initialization location of desc in xdma_channel_isr()
Date: Fri, 22 Dec 2023 11:06:45 -0700	[thread overview]
Message-ID: <20231222-dma-xilinx-xdma-clang-fixes-v1-2-84a18ff184d2@kernel.org> (raw)
In-Reply-To: <20231222-dma-xilinx-xdma-clang-fixes-v1-0-84a18ff184d2@kernel.org>

Clang warns (or errors with CONFIG_WERROR=y):

  drivers/dma/xilinx/xdma.c:894:3: error: variable 'desc' is uninitialized when used here [-Werror,-Wuninitialized]
    894 |                 desc->error = true;
        |                 ^~~~

The initialization of desc was moved too far forward, move it back so
that this assignment does not result in a potential crash at runtime
while clearing up the warning.

Closes: https://github.com/ClangBuiltLinux/linux/issues/1972
Fixes: 2f8f90cd2f8d ("dmaengine: xilinx: xdma: Implement interleaved DMA transfers")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/dma/xilinx/xdma.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/xilinx/xdma.c b/drivers/dma/xilinx/xdma.c
index d5b9fc3fd955..ee595d1ebc63 100644
--- a/drivers/dma/xilinx/xdma.c
+++ b/drivers/dma/xilinx/xdma.c
@@ -888,6 +888,8 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id)
 	if (ret)
 		goto out;
 
+	desc = to_xdma_desc(vd);
+
 	st &= XDMA_CHAN_STATUS_MASK;
 	if ((st & XDMA_CHAN_ERROR_MASK) ||
 	    !(st & (CHAN_CTRL_IE_DESC_COMPLETED | CHAN_CTRL_IE_DESC_STOPPED))) {
@@ -901,7 +903,6 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id)
 	if (ret)
 		goto out;
 
-	desc = to_xdma_desc(vd);
 	if (desc->interleaved_dma) {
 		xchan->busy = false;
 		desc->completed_desc_num += complete_desc_num;

-- 
2.43.0


WARNING: multiple messages have this Message-ID (diff)
From: Nathan Chancellor <nathan@kernel.org>
To: lizhi.hou@amd.com, brian.xu@amd.com, raj.kumar.rampelli@amd.com,
	 vkoul@kernel.org, jankul@alatek.krakow.pl
Cc: dmaengine@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	 llvm@lists.linux.dev, patches@lists.linux.dev,
	 Nathan Chancellor <nathan@kernel.org>
Subject: [PATCH 2/2] dmaengine: xilinx: xdma: Fix initialization location of desc in xdma_channel_isr()
Date: Fri, 22 Dec 2023 11:06:45 -0700	[thread overview]
Message-ID: <20231222-dma-xilinx-xdma-clang-fixes-v1-2-84a18ff184d2@kernel.org> (raw)
In-Reply-To: <20231222-dma-xilinx-xdma-clang-fixes-v1-0-84a18ff184d2@kernel.org>

Clang warns (or errors with CONFIG_WERROR=y):

  drivers/dma/xilinx/xdma.c:894:3: error: variable 'desc' is uninitialized when used here [-Werror,-Wuninitialized]
    894 |                 desc->error = true;
        |                 ^~~~

The initialization of desc was moved too far forward, move it back so
that this assignment does not result in a potential crash at runtime
while clearing up the warning.

Closes: https://github.com/ClangBuiltLinux/linux/issues/1972
Fixes: 2f8f90cd2f8d ("dmaengine: xilinx: xdma: Implement interleaved DMA transfers")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/dma/xilinx/xdma.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/xilinx/xdma.c b/drivers/dma/xilinx/xdma.c
index d5b9fc3fd955..ee595d1ebc63 100644
--- a/drivers/dma/xilinx/xdma.c
+++ b/drivers/dma/xilinx/xdma.c
@@ -888,6 +888,8 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id)
 	if (ret)
 		goto out;
 
+	desc = to_xdma_desc(vd);
+
 	st &= XDMA_CHAN_STATUS_MASK;
 	if ((st & XDMA_CHAN_ERROR_MASK) ||
 	    !(st & (CHAN_CTRL_IE_DESC_COMPLETED | CHAN_CTRL_IE_DESC_STOPPED))) {
@@ -901,7 +903,6 @@ static irqreturn_t xdma_channel_isr(int irq, void *dev_id)
 	if (ret)
 		goto out;
 
-	desc = to_xdma_desc(vd);
 	if (desc->interleaved_dma) {
 		xchan->busy = false;
 		desc->completed_desc_num += complete_desc_num;

-- 
2.43.0


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  parent reply	other threads:[~2023-12-22 18:06 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-12-22 18:06 [PATCH 0/2] dmaengine: xilinx: xdma: Fix two clang warnings Nathan Chancellor
2023-12-22 18:06 ` Nathan Chancellor
2023-12-22 18:06 ` [PATCH 1/2] dmaengine: xilinx: xdma: Fix operator precedence in xdma_prep_interleaved_dma() Nathan Chancellor
2023-12-22 18:06   ` Nathan Chancellor
2023-12-22 18:06 ` Nathan Chancellor [this message]
2023-12-22 18:06   ` [PATCH 2/2] dmaengine: xilinx: xdma: Fix initialization location of desc in xdma_channel_isr() Nathan Chancellor
2023-12-22 22:43 ` [PATCH 0/2] dmaengine: xilinx: xdma: Fix two clang warnings Jan Kuliga
2023-12-22 22:43   ` Jan Kuliga
2024-01-19 12:50 ` Vinod Koul
2024-01-19 12:50   ` Vinod Koul

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