Re: ath12k: REO status on PPC does not work

[Sebastian Gottschall <s.gottschall@dd-wrt.com>]

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.

Am 15.08.2025 um 10:13 schrieb Alexander Wilhelm:
> Hello devs,
>
> I'm currently working on getting the 'ath12k' driver running on a big endian
> PowerPC platform and have encountered the following issue.
>
> In the function 'ath12k_dp_rx_process_reo_status', the REO status is determined
> by inspecting memory that the hardware has previously written via DMA.
> Specifically, during the call to 'ath12k_hal_srng_access_begin', the driver
> reads the value of 'hp_addr' for the destination ring (in my case, always with
> ID 21). On the big endian platform, this value is consistently 0, which prevents
> the REO status from being updated.
>
> Interestingly, DMA read/write accesses work fine for other rings, just not for
> this one. What makes the REO status ring so special? I couldn’t find anything in
> the initialization routine that would explain the difference.
>
> Could anyone give me a hint on what I should be looking for?
>
>
> Best regards
> Alexander Wilhelm
>
>