Re: [PATCH] media: microchip: isc: Initialize DMA lock before requesting IRQ

[Runyu Xiao]

Hi Hans and Eugen,

Thanks for taking a look at this.

On Sun, 30 Aug 2026, I wrote:
> The ISC interrupt can run before asynchronous subdevice completion,
> but the DMA queue lock was initialized from isc_async_complete().
> Initialize it in each SoC probe before requesting the auto-enabled IRQ.

On Thu, 10 Sep 2026, Hans Verkuil wrote:
> It's dubious to just init dma_queue_lock here but not
> INIT_LIST_HEAD(&isc->dma_queue);
>
> I think Eugen needs to look at this as well to see if this is actually
> a valid issue at all.
>
> In any case, this patch doesn't look right to me.

You're right that moving dma_queue_lock alone is not enough. The interrupt
handler also accesses dma_queue, comp, and awb_work, which are initialized
later from isc_async_complete(). I also need to confirm whether an interrupt
can actually be pending at this point, and whether the required clocks and
hardware state are ready during probe.

I have not established that yet, so I'll drop this version for now rather
than send a v2 that only moves another initialization. Eugen, could you
please confirm the expected reset and interrupt state during probe? If there
is a real probe-time path, I'll revisit this with the complete ordering.

Thanks,
Runyu