Messages in this thread | | | Date | Thu, 18 Aug 2016 10:16:03 +0100 | From | Russell King - ARM Linux <> | Subject | Re: [PATCH v1 1/5] dma: Add QorIQ qDMA engine driver support |
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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."
-- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.
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