[PATCH] dmaengine: ti: k3-udma: Avoid false error msg on chan teardown

[Francesco Dolcini]

Hello Vignesh,
reviving this old email, since it seems that it raised a valid issue
that is still not resolved.

On Tue, Feb 15, 2022 at 10:11:12AM +0530, Vignesh Raghavendra wrote:
> In cyclic mode, there is no additional descriptor pushed to collect
> outstanding data on channel teardown. Therefore no need to wait for this
> descriptor to come back.
> 
> Without this terminating aplay cmd outputs false error msg like:
> [  116.402800] ti-bcdma 485c0100.dma-controller: chan1 teardown timeout!
I am experiencing a similar issue on Toradex Verdin AM62:

```
kern  :warn  : [   40.196661] ti-udma 485c0100.dma-controller: chan2 teardown timeout!
kern  :warn  : [   41.077013] kauditd_printk_skb: 14 callbacks suppressed
kern  :warn  : [   46.404672] ti-udma 485c0100.dma-controller: chan2 teardown timeout!
kern  :warn  : [   50.852643] ti-udma 485c0100.dma-controller: chan1 teardown timeout!
kern  :warn  : [   56.932709] ti-udma 485c0100.dma-controller: chan1 teardown timeout!
kern  :warn  : [   64.516797] ti-udma 485c0100.dma-controller: chan1 teardown timeout!
kern  :warn  : [   70.404724] ti-udma 485c0100.dma-controller: chan1 teardown timeout!
kern  :warn  : [   71.588933] ti-udma 485c0100.dma-controller: chan2 teardown timeout!
kern  :warn  : [   75.908818] ti-udma 485c0100.dma-controller: chan1 teardown timeout!
kern  :warn  : [   77.064761] ti-udma 485c0100.dma-controller: chan2 teardown timeout!
```

I would say just the same, since this happens everytime aplay terminates.

Any idea to progress on this?

Francesco