[PATCH 6.6 034/254] dmaengine: xilinx_dma: Fix uninitialized addr_width when "xlnx,addrwidth" property is missing

Greg Kroah-Hartman
2026-01-28T15:30:36Z

From: Suraj Gupta <suraj.gupta2@amd.com>

[ Upstream commit c0732fe78728718c853ef8e7af5bbb05262acbd1 ]

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 <suraj.gupta2@amd.com>
Fixes: b72db4005fe4 ("dmaengine: vdma: Add 64 bit addressing support to the driver")
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@amd.com>
Reviewed-by: Folker Schwesinger <dev@folker-schwesinger.de>
Link: https://patch.msgid.link/20251021183006.3434495-1-suraj.gupta2@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 14c4c5031b556..176cac3f37a73 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -128,6 +128,7 @@
#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 | \
@@ -3057,7 +3058,7 @@ 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 */
@@ -3131,7 +3132,9 @@ 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;
--
2.51.0