Thread (3 messages) 3 messages, 3 authors, 2025-09-05

Re: [PATCH] dmaengine: xilinx_dma: Fix uninitialized addr_width when "xlnx,addrwidth" property is missing

From: Folker Schwesinger <hidden>
Date: 2025-09-05 10:16:41
Also in: dmaengine, lkml

On Fri Sep 5, 2025 at 8:48 AM CEST, Suraj Gupta wrote:
When device tree lacks optional "xlnx,addrwidth" property, the addr_width
variable remained uninitialized with garbage values, causing incorrect
DMA mask configuration and subsequent probe failure. The fix ensures a
fallback to the default 32-bit address width when this property is missing.

Signed-off-by: Suraj Gupta <redacted>
Fixes: b72db4005fe4 ("dmaengine: vdma: Add 64 bit addressing support to the driver")
Reviewed-by: Folker Schwesinger <redacted>
quoted hunk ↗ jump to hunk
---
 drivers/dma/xilinx/xilinx_dma.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index fabff602065f..89a8254d9cdc 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -131,6 +131,7 @@
 #define XILINX_MCDMA_MAX_CHANS_PER_DEVICE	0x20
 #define XILINX_DMA_MAX_CHANS_PER_DEVICE		0x2
 #define XILINX_CDMA_MAX_CHANS_PER_DEVICE	0x1
+#define XILINX_DMA_DFAULT_ADDRWIDTH		0x20
 
 #define XILINX_DMA_DMAXR_ALL_IRQ_MASK	\
 		(XILINX_DMA_DMASR_FRM_CNT_IRQ | \
@@ -3159,7 +3160,7 @@ static int xilinx_dma_probe(struct platform_device *pdev)
 	struct device_node *node = pdev->dev.of_node;
 	struct xilinx_dma_device *xdev;
 	struct device_node *child, *np = pdev->dev.of_node;
-	u32 num_frames, addr_width, len_width;
+	u32 num_frames, addr_width = XILINX_DMA_DFAULT_ADDRWIDTH, len_width;
 	int i, err;
 
 	/* Allocate and initialize the DMA engine structure */
@@ -3235,7 +3236,9 @@ static int xilinx_dma_probe(struct platform_device *pdev)
 
 	err = of_property_read_u32(node, "xlnx,addrwidth", &addr_width);
 	if (err < 0)
-		dev_warn(xdev->dev, "missing xlnx,addrwidth property\n");
+		dev_warn(xdev->dev,
+			 "missing xlnx,addrwidth property, using default value %d\n",
+			 XILINX_DMA_DFAULT_ADDRWIDTH);
 
 	if (addr_width > 32)
 		xdev->ext_addr = true;
  
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help