Re: [PATCH] dmaengine: stm32-mdma: Add missing check for device_property_read_u32_array
From: Amelie Delaunay <amelie.delaunay@foss.st.com>
Date: 2026-01-28 10:24:32
Also in:
dmaengine, lkml
On 1/28/26 05:23, Chen Ni wrote:
quoted hunk ↗ jump to hunk
Add check for the return value of device_property_read_u32_array() and return the error if it fails in order to catch the error. Signed-off-by: Chen Ni <redacted> --- drivers/dma/stm32/stm32-mdma.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)diff --git a/drivers/dma/stm32/stm32-mdma.c b/drivers/dma/stm32/stm32-mdma.c index b87d41b234df..f833724cf42c 100644 --- a/drivers/dma/stm32/stm32-mdma.c +++ b/drivers/dma/stm32/stm32-mdma.c@@ -1630,9 +1630,11 @@ static int stm32_mdma_probe(struct platform_device *pdev) dmadev->nr_channels = nr_channels; dmadev->nr_requests = nr_requests; - device_property_read_u32_array(&pdev->dev, "st,ahb-addr-masks", - dmadev->ahb_addr_masks, - count); + ret = device_property_read_u32_array(&pdev->dev, "st,ahb-addr-masks", + dmadev->ahb_addr_masks, + count); + if (ret) + return ret;
Your patch breaks MDMA on STM32MP1x platforms because "st,ahb-addr-masks" is an optional property. That is why the return value of device_property_read_u32_array() is intentionally ignored. Count is used to check the presence of the property and to allocate dmadev->ahb_addr_masks accordingly: count = device_property_count_u32(&pdev->dev, "st,ahb-addr-masks"); if (count < 0) count = 0; [...] dmadev->nr_ahb_addr_masks = count; If the property is not present, dmadev->nr_ahb_addr_masks is set to 0, and MDMA behaves correctly. With your patch, when the property is missing, the MDMA probe fails because device_property_read_u32_array() returns -EINVAL. This is incorrect since "st,ahb-addr-masks" is an optional property, not a required one. Regards, Amelie
dmadev->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(dmadev->base))