[PATCH v1 1/5] dma: Add QorIQ qDMA engine driver support
Yao Yuan
yao.yuan at nxp.com
Tue Aug 23 20:39:11 PDT 2016
On Thu, Aug 18, 2016 at 05:16 PM +0800, Russell King wrote:
> On Thu, Aug 18, 2016 at 02:38:44PM +0800, Yuan Yao wrote:
> > + spin_lock(&fsl_comp->qchan->vchan.lock);
> > + if (status == DMA_COMPLETE)
> > + vchan_cookie_complete(&fsl_comp->vdesc);
> > + fsl_comp->qchan->status = status;
>
> This is buggy - if the DMA has finished processing it, even if it finished in error, it
> must _complete_ the transaction. Completion is not the same as being
> successful - it means that the DMA is no longer processing the cookie.
>
> The issue here is that when the _following_ transaction completes successfully,
> _this_ transaction will effectively be marked as complete due to the way the
> cookie system works.
>
> So... to get this straight - "completion" means "I have finished processing this
> transaction". It does not mean "I successfully processed this transaction
> without any errors."
>
Thanks for your review.
So you mean that I should call vchan_cookie_complete no matter whether the error issue in QDMA?
I have some random DMA error test case, it seems work will.
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