Re: [PATCH v3 1/2] arm64: dts: imx95: Reserve eDMA channels 0-1 for V2X
From: Laurentiu Mihalcea <hidden>
Date: 2026-02-03 10:17:03
Also in:
imx, linux-arm-kernel, lkml
On 2/1/2026 7:22 PM, Peng Fan wrote:
Hi Joy, Sorry to jump in at V3. On Fri, Jan 30, 2026 at 05:36:27PM +0800, Joy Zou wrote:quoted
Reserve eDMA channels 0 and 1 on the AXI eDMA controller for exclusive use by V2X (Vehicle-to-Everything) fast hash operations. Reviewed-by: Laurentiu Mihalcea <redacted> Tested-by: Laurentiu Mihalcea <redacted> Signed-off-by: Joy Zou <redacted> --- arch/arm64/boot/dts/freescale/imx95.dtsi | 2 ++ 1 file changed, 2 insertions(+)diff --git a/arch/arm64/boot/dts/freescale/imx95.dtsi b/arch/arm64/boot/dts/freescale/imx95.dtsi index 55e2da094c889fc7c1096d0e36f31ae118d2a982..9ac82da2ff440e08ae8378d7ff830a568d50a354 100644 --- a/arch/arm64/boot/dts/freescale/imx95.dtsi +++ b/arch/arm64/boot/dts/freescale/imx95.dtsi@@ -631,6 +631,8 @@ edma2: dma-controller@42000000 {reg = <0x42000000 0x210000>; #dma-cells = <3>; dma-channels = <64>; + /* channels 0 and 1 reserved for V2X fast hash */ + dma-channel-mask = <0x3>;This is wrong. Per dt-binding, dma-channel-mask means Bitmask of available DMA channels in ascending order, The usage in this patch does not match the dt-binding.
Ah, good catch. It would seem like our EDMA driver reverses the meaning of the "dma-channel-mask" bits (i.e. bit x set means channel x reserved instead of channel x available). Now, I wonder how we should be proceeding with this. According to the DT binding, our devicetree configurations are wrong. Since there seem to be only 8 upstream instances in which this property is being used I guess it wouldn't be so difficult to correct the driver's behavior and then correct the devicetrees?