Re: ath12k: REO status on PPC does not work

[Alexander Wilhelm <alexander.wilhelm@westermo.com>]

Am Fri, Aug 15, 2025 at 11:55:14AM +0200 schrieb Sebastian Gottschall:
> i played already with big endian platforms and ath11k (not ath12k) for
> months. there is also a problem with the dma descriptors. the firmware
> simply doesnt support big endian with host communication at the end even if
> there is a endian flag for the firmware.  dont get into this rabit hole. (i
> worked 3 months on it and gave up)
> at the end (i was working on a cavium octeon platform at that time) i just
> switched the kernel boot to little endian which is possible on many ppc
> platforms too.

The 'ath11k' driver works a bit differently. The endian swap is implemented in
the firmware and was never properly tested. My investigations show that the
firmware does not handle the swap consistently. According to 'kvalo', different
firmware versions treat the swap differently. See [1].

With 'ath12k', the situation looks better. Unfortunately, there are still some
memcpys from u32 to u8 or similar. Also, reading from DMA memory is not swapped.
I already have ath12k running, I get ping responses and can transmit data.
However, not in all modes, and there are still some bugs I’m trying to iron out.


Best regards
Alexander Wilhelm

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[1] https://lore.kernel.org/ath11k/68290980-5bfb-c88c-be78-954f9591c135@westermo.com/T/#u