Re: [PATCH v3] dt-bindings: misc: add binding for Xilinx AXI-Stream FIFO

From: Krzysztof Kozlowski

Date: Sun Jun 21 2026 - 14:33:41 EST


On 21/06/2026 11:43, Aditya Chari wrote:
> The axis-fifo driver's compatible strings were undocumented, flagged
> by checkpatch.pl as UNDOCUMENTED_DT_STRING. Add a YAML devicetree
> binding document for drivers/staging/axis-fifo, converted from and
> replacing the existing free-form text binding (axis-fifo.txt), which
> this patch removes.
>
> Constrain xlnx,tx-fifo-depth to a minimum of 4, since the driver
> subtracts 4 from this value in its transmit bounds check and a
> smaller value would underflow that check.
>
> Signed-off-by: Aditya Chari <adi25charis@xxxxxxxxx>
> ---
>
> Changes since v2:
> - Added $ref: /schemas/types.yaml#/definitions/string to the three
> AXI-Stream protocol enum properties (xlnx,axi-str-rxd-protocol,
> xlnx,axi-str-txd-protocol, xlnx,axi-str-txc-protocol) for explicit
> type consistency with the rest of the schema.
> - Added minimum: 4 to xlnx,tx-fifo-depth, since the driver subtracts
> 4 from this value in its transmit bounds check
> (axis_fifo_write()) and a smaller configured value would underflow
> that unsigned check, bypassing the oversized-packet guard.
>
> Changes since v1:
> - Fixed xlnx,rx/tx-fifo-depth: depth is in 32-bit words, not bytes,
> matching the driver's overflow check in axis_fifo_write() and the
> wording of the original text binding.
> - Restored the full set of hardware-generated properties (interrupt-
> names, AXI-Stream protocol/width properties, has-axis-t* feature
> flags, fifo threshold properties, etc.) so that additionalProperties:
> false does not reject valid device trees generated for real hardware.
> - Removed the now-superseded axis-fifo.txt text binding.

Please slow down. Three versions within 1 hour! Why sending something
and immediately sending fixes to it?

>
> .../bindings/misc/xlnx,axi-fifo-mm-s.yaml | 227 ++++++++++++++++++
> drivers/staging/axis-fifo/axis-fifo.txt | 96 --------

Why are you touching staging binding?

https://lore.kernel.org/all/?q=dfn%3Aaxis-fifo.txt

Best regards,
Krzysztof