Re: [PATCH v3 00/34] dmaengine: migrate channel tasklets to WQ_BH

[Andy Shevchenko]

On Tue, Aug 11, 2026 at 01:44:49PM -0700, Allen wrote:

...

> > > The remaining patches convert driver-owned channel completion tasklets.
> > > Tasklets used for controller-level processing, recovery, or other
> > > non-client-callback work are deliberately left alone because the
> > > appropriate replacement may differ by driver.
> >
> > Right, I would actually expect that virt-dma (and others will follow the
> > example) will switch to threaded IRQ instead of tasklets.
> 
>   I had not considered a full virt-dma conversion for this series. Looking
>   at the driver, that would also involve its descriptor pool, queue and
>   active lists, software LLP and cyclic handling, and residue reporting. It
>   would therefore be a substantially broader change than moving callback
>   delivery to the common channel BH.
> 
>   My intention here was to leave the existing descriptor lifecycle and
>   scheduling unchanged and only move callback invocation out of the
>   controller tasklet. I think converting the driver to virt-dma would be
>   better handled as a separate series with hardware testing.
> 
>   If you would prefer not to add the completed list ahead of such a
>   conversion, I can drop this patch from the current series and leave the
>   DW driver unchanged for now.

I think this is unneeded churn for DW DMA driver. It requires a much bigger
refactoring and cleaning up.

-- 
With Best Regards,
Andy Shevchenko