Re: ath12k: REO status on PPC does not work

[Baochen Qiang <baochen.qiang@oss.qualcomm.com>]

On 8/15/2025 4:13 PM, Alexander Wilhelm wrote:
> 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.

This does not seem an endian issue to me, because either of them we should get a value
other than 0.

> 
> 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?
> 
> 
What hardware are you using? WCN7850 or QCN9274?

> Best regards
> Alexander Wilhelm
>