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Sashiko AI review found 1 potential issue(s) to consider: > - [High] Ring buffer capacity is permanently leaked on error and termination paths because `ll_end` is not advanced. > -- > > --- Patch [4]: [PATCH v2 04/19] dmaengine: dw-edma: Make DMA link list work as a circular buffer --- > commit 2d5b6554b58830487f70a13eab5e1ac3de304658 > Author: Frank Li > > dmaengine: dw-edma: Make DMA link list work as a circular buffer > > This commit updates the driver to use the DMA linked list as a circular > ring buffer. It appends entries at ll_head with the current cycle bit and > reserves the final entry to link back to the start. > > > diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c > > --- a/drivers/dma/dw-edma/dw-edma-core.c > > +++ b/drivers/dma/dw-edma/dw-edma-core.c > > [ ... ] > > > @@ -645,6 +687,8 @@ static void dw_edma_done_interrupt(struct dw_edma_chan *chan) > > DMA_TRANS_NOERROR); > > list_del(&vd->node); > > vchan_cookie_complete(vd); > > + if (!chan->non_ll) > > + chan->ll_end = chan->ll_head; > > } > > > > if (chan->request == EDMA_REQ_PAUSE) { > > [Severity: High] > Does this leak ring capacity when descriptors are aborted or terminated? > > This block successfully reclaims ring capacity on successful completion by > advancing chan->ll_end. However, if a client driver queues transfers and > then aborts them (for example, via dmaengine_terminate_all() or during an > abort interrupt), the descriptors are removed from the list but chan->ll_end > does not appear to be updated to reflect the aborted descriptors. > > Since chan->ll_valid remains true after a termination, subsequent transfers > will bypass the dw_edma_core_reset_ll() ring reset logic and continue > appending to the un-reclaimed ring. Make sense. Need change at these abnormal case. Frank > > Will this eventually cause dw_edma_core_get_free_num() to permanently return > 0 and deadlock the channel once the un-reclaimed slots exhaust the ring? > > -- > Sashiko AI review · https://sashiko.dev/#/patchset/20260723084150.521366-1-den@valinux.co.jp?part=4