Re: [PATCH v5 1/4] dt-bindings: dma: xlnx,zynqmp-dma: Require resets for Versal Gen2
From: Rob Herring (Arm)
Date: Fri Nov 06 2026 - 09:28:50 EST
On Fri, 06 Nov 2026 15:40:23 +0530, Golla Nagendra wrote:
> Require the per-channel resets property for Versal Gen2
> DMA devices, which expose dedicated reset lines.
>
> Making resets required for Versal Gen2 results in an ABI break, but this
> is unavoidable. While the driver works in many scenarios when no other
> firmware has used the DMA prior to Linux boot, there is no guarantee the
> channel is left in a clean state. In observed error scenarios, a reset is
> necessary before Linux can reconfigure the IP after previous use by other
> firmware components. Due to configuration differences or the DMA being
> left in a bad state, DMA functionality fails when sequential software
> components use the channel (e.g., firmware before Linux boot). The channel
> can only be cleanly re-configured after a per-channel reset, making it
> essential. This ABI break is only applied to Versal Gen2 and where the
> per-channel reset capability is available.
>
> Fixes: 36545c6a68b8 ("dt-bindings: dmaengine: zynqmp_dma: Add a new compatible string")
> Signed-off-by: Golla Nagendra <nagendra.golla@xxxxxxx>
> ---
> .../bindings/dma/xilinx/xlnx,zynqmp-dma-1.0.yaml | 21 ++++++++++++++++++---
> 1 file changed, 18 insertions(+), 3 deletions(-)
>
Reviewed-by: Rob Herring (Arm) <robh@xxxxxxxxxx>