[PATCH net 2/2] net/stmmac: Verify provided DTS AXI setup

Andrew Lunn andrew at lunn.ch
Tue Jul 7 12:04:00 PDT 2026


On Tue, Jul 07, 2026 at 07:44:31PM +0200, Jakub Raczynski wrote:
> During parsing of AXI setup, there are few issues:
> - 'axi_blen' array is uninitialized value on stack without zero-init stack
>   configured. This can result in random AXI burst length config if
>   DTS config provides shorter array than AXI_BLEN.

What does the DT blinding say about the length? Is it allowed to be
short?

Are we talking about:

      snps,blen:
        $ref: /schemas/types.yaml#/definitions/uint32-array
        description:
          this is a vector of supported burst length.
        minItems: 7
        maxItems: 7

So it should be 7. Are there any in kernel DT blobs which don't pass
7? Can we just error out when it is not 7?

> - In case of failed memory allocation for AXI and error, there is no handling
>   of that. Fix it by checking if AXI config is error and return if so,
>   as this can only lack of memory. No AXI config, although is probably
>   wrong in most cases, is not treated as error, as generic config is mostly
>   provided in drivers.

This seems like a different fix. Maybe put it into a patch of its own.

> Fixes: afea03656add ("stmmac: rework DMA bus setting and introduce new platform AXI structure")

Again, does this bother anybody? At least axi_blen issue seems to be
that the DT blob is broken, so i doubt it actually does. Are there
reports of memory allocation error and resulting Opps.


    Andrew

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