Re: [PATCH v6 2/4] dmaengine: mediatek-cqdma: remove redundant queue structure
From: EastL <hidden>
Date: 2020-07-23 02:34:17
Also in:
dmaengine, linux-devicetree, linux-mediatek, lkml
On Wed, 2020-07-15 at 11:49 +0530, Vinod Koul wrote:
On 02-07-20, 15:06, EastL Lee wrote:quoted
static enum dma_status mtk_cqdma_tx_status(struct dma_chan *c, dma_cookie_t cookie, struct dma_tx_state *txstate) { - struct mtk_cqdma_vchan *cvc = to_cqdma_vchan(c); - struct mtk_cqdma_vdesc *cvd; - struct virt_dma_desc *vd; - enum dma_status ret; - unsigned long flags; - size_t bytes = 0; - - ret = dma_cookie_status(c, cookie, txstate); - if (ret == DMA_COMPLETE || !txstate) - return ret; - - spin_lock_irqsave(&cvc->vc.lock, flags); - vd = mtk_cqdma_find_active_desc(c, cookie); - spin_unlock_irqrestore(&cvc->vc.lock, flags); - - if (vd) { - cvd = to_cqdma_vdesc(vd); - bytes = cvd->residue; - } - - dma_set_residue(txstate, bytes);any reason why you want to remove setting residue?
Because Mediatek CQDMA HW can't support residue.
quoted
-static void mtk_cqdma_free_active_desc(struct dma_chan *c) +static int mtk_cqdma_terminate_all(struct dma_chan *c) { struct mtk_cqdma_vchan *cvc = to_cqdma_vchan(c); - bool sync_needed = false; + struct virt_dma_chan *vc = to_virt_chan(c); unsigned long pc_flags; unsigned long vc_flags; + LIST_HEAD(head); + + /* wait for the VC to be inactive */ + if (!wait_for_completion_timeout(&cvc->cmp, msecs_to_jiffies(3000))) + return -EAGAIN; /* acquire PC's lock first due to lock dependency in dma ISR */ spin_lock_irqsave(&cvc->pc->lock, pc_flags); spin_lock_irqsave(&cvc->vc.lock, vc_flags); - /* synchronization is required if this VC is active */ - if (mtk_cqdma_is_vchan_active(cvc)) { - cvc->issue_synchronize = true; - sync_needed = true; - } + /* get VDs from lists */ + vchan_get_all_descriptors(vc, &head); + + /* free all the VDs */ + vchan_dma_desc_free_list(vc, &head); spin_unlock_irqrestore(&cvc->vc.lock, vc_flags); spin_unlock_irqrestore(&cvc->pc->lock, pc_flags);Good cleanup, do you need both these locks?
Yes, because we will have multiple vc to pc, it will need both lock. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel