Re: [PATCH v2 ath-next 2/2] wifi: ath11k: fix HTC rx insufficient length

[Johan Hovold <johan@kernel.org>]

On Thu, Mar 13, 2025 at 09:41:51AM +0800, Miaoqing Pan wrote:
> On 3/13/2025 12:43 AM, Johan Hovold wrote:

> > I've taken a closer look at the driver and it seems like we're missing a
> > read barrier to make sure that the updated descriptor is not read until
> > after the head pointer.
> > 
> > Miaoqing, could you try the below patch with your reproducer and see if
> > it is enough to fix the corruption?
>
> Sure, the stress test is running.

Thanks.

> > If so I can resend with the warning removed and include a corresponding
> > fix for ath12k (it looks like there are further places where barriers
> > are missing too).

> If the DMA read barrier works, do you think my submitted patch series is 
> still needed? Because the error handling is incorrect.

Yeah, it would still be good to fix up the error handling even if you
don't expect to ever see a descriptor with length 0.

But unless the device is doing something wrong here, there shouldn't be
a need for peeking at the descriptor and retrying.

Johan