Lars-Peter Clausen <lars@xxxxxxxxxx> writes: > On 03/02/2015 10:19 PM, Robert Jarzmik wrote: >> diff --git a/drivers/dma/virt-dma.h b/drivers/dma/virt-dma.h >> index 3772032..2a3da22 100644 >> --- a/drivers/dma/virt-dma.h >> +++ b/drivers/dma/virt-dma.h >> @@ -91,7 +91,7 @@ static inline void vchan_cookie_complete(struct virt_dma_desc *vd) >> dma_cookie_complete(&vd->tx); >> dev_vdbg(vc->chan.device->dev, "txd %p[%x]: marked complete\n", >> vd, cookie); >> - list_add_tail(&vd->node, &vc->desc_completed); >> + list_move_tail(&vd->node, &vc->desc_completed); > > That will break all drivers which handle this currently correctly and remove the > descriptor from any list before calling vchan_cookie_complete. Ah, well well I don't agree. First, let's split the drivers which remove the descriptors and these which don't : These which remove the descriptor: dma-jz4740.c fsl-edma.c These which don't remove the descriptor: amba-pl08x.c edma.c img-mdc-dma.c k3dma.c moxart-dma.c omap-dma.c qcom_bam_dma.c s3c24xx-dma.c sa11x0-dma.c sun6i-dma.c That settles the correctness I think, the correct behavior is to not remove the descriptor and let it be done by vchan_cookie_complete(). Now for the remaining 2 drivers, we'll have : - list_del(&vd->node) => vd becomes a singleton - list_move_tail(&vd->node, &...desc_completed) => list_del(&vd->node) : nothing changes, it's a nop => list_add_tail(&vd->node, &...desc_completed) And the behavior remains correct after the patch, only one "list_del()" is done twice for nothing. Where do you see any breakage ? Cheers. -- Robert -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
