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From: Frank Li <Frank.li@oss.nxp.com>
To: Koichiro Den <den@valinux.co.jp>
Cc: "Manivannan Sadhasivam" <mani@kernel.org>,
	"Vinod Koul" <vkoul@kernel.org>, "Frank Li" <Frank.Li@kernel.org>,
	"Gustavo Pimentel" <Gustavo.Pimentel@synopsys.com>,
	"Kees Cook" <kees@kernel.org>,
	"Krzysztof Wilczyński" <kwilczynski@kernel.org>,
	"Kishon Vijay Abraham I" <kishon@kernel.org>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Christoph Hellwig" <hch@lst.de>,
	"Serge Semin" <fancer.lancer@gmail.com>,
	"Cai Huoqing" <cai.huoqing@linux.dev>,
	"Niklas Cassel" <cassel@kernel.org>,
	"Devendra K Verma" <devendra.verma@amd.com>,
	dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 07/19] dmaengine: dw-edma: Dispatch DONE interrupts by channel request
Date: Thu, 23 Jul 2026 11:57:32 -0500	[thread overview]
Message-ID: <amJH_IknotEHF5Nr@SMW015318> (raw)
In-Reply-To: <20260723084150.521366-8-den@valinux.co.jp>

On Thu, Jul 23, 2026 at 05:41:38PM +0900, Koichiro Den wrote:

Subject:

Check channel request firstly at DONE channel interrupts ?

> Handle the channel request first in the DONE interrupt path, then look
> at the issued descriptor list only in the cases that need it.
>
> This keeps the existing behavior, including the current STOP and PAUSE
> handling when no issued descriptor is present.

Need descript why need this change?

Frank
>
> No functional change intended.
>
> Signed-off-by: Koichiro Den <den@valinux.co.jp>
> ---
> Changes in v2:
>   - Limit this patch to request dispatch with no functional change;
>     move LL progress and empty-issued-list handling to later patches.
>
>  drivers/dma/dw-edma/dw-edma-core.c | 60 +++++++++++++++---------------
>  1 file changed, 31 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
> index 29f78405e9fb..fa104af4146e 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-core.c
> @@ -682,41 +682,43 @@ static void dw_edma_done_interrupt(struct dw_edma_chan *chan)
>  		return;
>  	}
>
> -	vd = vchan_next_desc(&chan->vc);
> -	if (vd) {
> -		switch (chan->request) {
> -		case EDMA_REQ_NONE:
> -		case EDMA_REQ_PAUSE:
> -			desc = vd2dw_edma_desc(vd);
> -			if (desc->start_burst >= desc->nburst) {
> -				dw_hdma_set_callback_result(vd,
> -							    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) {
> -				chan->request = EDMA_REQ_NONE;
> -				chan->status = EDMA_ST_PAUSE;
> -				break;
> -			}
> -
> -			/* Continue transferring if there are remaining chunks or issued requests.
> -			 */
> -			chan->status = dw_edma_start_transfer(chan) ? EDMA_ST_BUSY : EDMA_ST_IDLE;
> +	switch (chan->request) {
> +	case EDMA_REQ_NONE:
> +	case EDMA_REQ_PAUSE:
> +		vd = vchan_next_desc(&chan->vc);
> +		if (!vd)
>  			break;
>
> -		case EDMA_REQ_STOP:
> -			dw_edma_terminate_all_descs(chan);
> +		desc = vd2dw_edma_desc(vd);
> +		if (desc->start_burst >= desc->nburst) {
> +			dw_hdma_set_callback_result(vd, 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) {
>  			chan->request = EDMA_REQ_NONE;
> -			chan->status = EDMA_ST_IDLE;
> +			chan->status = EDMA_ST_PAUSE;
>  			break;
> +		}
>
> -		default:
> +		chan->status = dw_edma_start_transfer(chan) ? EDMA_ST_BUSY : EDMA_ST_IDLE;
> +		break;
> +
> +	case EDMA_REQ_STOP:
> +		vd = vchan_next_desc(&chan->vc);
> +		if (!vd)
>  			break;
> -		}
> +
> +		dw_edma_terminate_all_descs(chan);
> +		chan->request = EDMA_REQ_NONE;
> +		chan->status = EDMA_ST_IDLE;
> +		break;
> +
> +	default:
> +		break;
>  	}
>  	spin_unlock_irqrestore(&chan->vc.lock, flags);
>  }
> --
> 2.51.0
>

  parent reply	other threads:[~2026-07-23 16:57 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-23  8:41 [PATCH v2 00/19] dmaengine: dw-edma: Support dynamic LL appends Koichiro Den
2026-07-23  8:41 ` [PATCH v2 01/19] dmaengine: dw-edma: Add dw_edma_core_ll_cur_idx() to get current LL entry index Koichiro Den
2026-07-23 16:25   ` Frank Li
2026-07-23  8:41 ` [PATCH v2 02/19] dmaengine: dw-edma: Add dw_edma_core_ll_clear() to clear LL control-word Koichiro Den
2026-07-23 18:53   ` Frank Li
2026-07-23  8:41 ` [PATCH v2 03/19] dmaengine: dw-edma: Factor out linked-list transfer start Koichiro Den
2026-07-23 16:31   ` Frank Li
2026-07-23  8:41 ` [PATCH v2 04/19] dmaengine: dw-edma: Make DMA link list work as a circular buffer Koichiro Den
2026-07-23  9:07   ` sashiko-bot
2026-07-23 16:43     ` Frank Li
2026-07-23  8:41 ` [PATCH v2 05/19] dmaengine: dw-edma: Add LL interrupt placement policy Koichiro Den
2026-07-23 19:58   ` Frank Li
2026-07-23  8:41 ` [PATCH v2 06/19] dmaengine: dw-edma: Move callback result helper before LL helpers Koichiro Den
2026-07-23 16:51   ` Frank Li
2026-07-23  8:41 ` [PATCH v2 07/19] dmaengine: dw-edma: Dispatch DONE interrupts by channel request Koichiro Den
2026-07-23  8:55   ` sashiko-bot
2026-07-23 16:57   ` Frank Li [this message]
2026-07-23  8:41 ` [PATCH v2 08/19] dmaengine: dw-edma: Centralize LL doorbell decisions Koichiro Den
2026-07-23  9:09   ` sashiko-bot
2026-07-23 17:02   ` Frank Li
2026-07-23  8:41 ` [PATCH v2 09/19] dmaengine: dw-edma: Reclaim issued descriptors from IRQ-paired LL progress Koichiro Den
2026-07-23  9:01   ` sashiko-bot
2026-07-23 20:56   ` Frank Li
2026-07-23  8:41 ` [PATCH v2 10/19] dmaengine: dw-edma: Use HDMA watermarks as progress events Koichiro Den
2026-07-23  8:41 ` [PATCH v2 11/19] dmaengine: dw-edma: Reconcile lost completions from a stopped LLP re-sample Koichiro Den
2026-07-23  8:41 ` [PATCH v2 12/19] dmaengine: dw-edma: Recover stopped channels from tx_status() Koichiro Den
2026-07-23  8:59   ` sashiko-bot
2026-07-23  8:41 ` [PATCH v2 13/19] dmaengine: dw-edma: Make the LL ring reset a full channel resync Koichiro Den
2026-07-23  9:10   ` sashiko-bot
2026-07-23  8:41 ` [PATCH v2 14/19] dmaengine: dw-edma: Reset LL state after terminate and abort Koichiro Den
2026-07-23  9:14   ` sashiko-bot
2026-07-23  8:41 ` [PATCH v2 15/19] dmaengine: dw-edma: Add engine reset and enable operations Koichiro Den
2026-07-23  9:11   ` sashiko-bot
2026-07-23  8:41 ` [PATCH v2 16/19] dmaengine: dw-edma: Add engine recovery infrastructure Koichiro Den
2026-07-23  9:14   ` sashiko-bot
2026-07-23  8:41 ` [PATCH v2 17/19] dmaengine: dw-edma: Detect and recover a stalled eDMA engine Koichiro Den
2026-07-23  9:12   ` sashiko-bot
2026-07-23  8:41 ` [PATCH v2 18/19] dmaengine: dw-edma: Dynamically append requests while running Koichiro Den
2026-07-23  8:41 ` [PATCH v2 19/19] dmaengine: dw-edma: Add trace support Koichiro Den
2026-07-23  9:11   ` sashiko-bot

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