From: sashiko-bot@kernel.org
To: "Koichiro Den" <den@valinux.co.jp>
Cc: vkoul@kernel.org, Frank.Li@kernel.org, dmaengine@vger.kernel.org
Subject: Re: [PATCH v2 07/19] dmaengine: dw-edma: Dispatch DONE interrupts by channel request
Date: Thu, 23 Jul 2026 08:55:33 +0000 [thread overview]
Message-ID: <20260723085534.6EBC51F000E9@smtp.kernel.org> (raw)
In-Reply-To: <20260723084150.521366-8-den@valinux.co.jp>
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
Pre-existing issues:
- [High] Channel state machine can get permanently stuck if a delayed interrupt arrives after a termination timeout (or if the interrupt never arrives).
--
--- Patch [7]: [PATCH v2 07/19] dmaengine: dw-edma: Dispatch DONE interrupts by channel request ---
commit 820c52e0edf662b1111ec33a334d76d30c13a546
Author: Koichiro Den <den@valinux.co.jp>
dmaengine: dw-edma: Dispatch DONE interrupts by channel request
This patch modifies the DONE interrupt path to handle the channel request
first before looking at the issued descriptor list. The change is intended
to keep the existing behavior without introducing functional changes.
> --- 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)
[ ... ]
> + case EDMA_REQ_STOP:
> + vd = vchan_next_desc(&chan->vc);
> + if (!vd)
> break;
[Severity: High]
This is a pre-existing issue, but does this early break leave the channel
permanently stuck in EDMA_ST_BUSY if a delayed interrupt arrives after a
termination timeout?
If a driver calls dmaengine_terminate_sync() and the hardware hangs,
dw_edma_wait_termination() will time out. Then
dw_edma_free_chan_resources() calls vchan_free_chan_resources(),
clearing the descriptor list.
If a delayed interrupt arrives afterward, dw_edma_done_interrupt() handles
EDMA_REQ_STOP but hits this if (!vd) check because the list is now empty.
By breaking early, the code skips resetting chan->request = EDMA_REQ_NONE
and chan->status = EDMA_ST_IDLE. Will this cause subsequent calls to
dw_edma_alloc_chan_resources() to fail with -EBUSY and permanently leak
the DMA channel resource?
> +
> + 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);
> }
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260723084150.521366-1-den@valinux.co.jp?part=7
next prev parent reply other threads:[~2026-07-23 8:55 UTC|newest]
Thread overview: 31+ 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 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 8:41 ` [PATCH v2 03/19] dmaengine: dw-edma: Factor out linked-list transfer start Koichiro Den
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 8:41 ` [PATCH v2 05/19] dmaengine: dw-edma: Add LL interrupt placement policy Koichiro Den
2026-07-23 8:41 ` [PATCH v2 06/19] dmaengine: dw-edma: Move callback result helper before LL helpers Koichiro Den
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 [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 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 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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