From: sashiko-bot@kernel.org
To: "Rosen Penev" <rosenp@gmail.com>
Cc: Frank.Li@kernel.org, dmaengine@vger.kernel.org, vkoul@kernel.org
Subject: Re: [PATCH] dmaengine: at_hdmac: use more devm in _probe
Date: Thu, 23 Jul 2026 05:16:43 +0000 [thread overview]
Message-ID: <20260723051643.F34461F000E9@smtp.kernel.org> (raw)
In-Reply-To: <20260723050732.290935-1-rosenp@gmail.com>
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] DMA channels are manually unlinked from the device list before devres executes `dmaenginem_async_device_unregister()`, leading to permanent memory leaks and sysfs name conflicts that break driver reload.
--
--- Patch [1]: [PATCH] dmaengine: at_hdmac: use more devm in _probe ---
commit c530cb83f3773c6a30cecc88fcb10f7ec0a53e60
Author: Rosen Penev <rosenp@gmail.com>
dmaengine: at_hdmac: use more devm in _probe
As devm is already used in _probe, complete the conversion so that
everything unwinds in proper order.
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index e5b30a57c477a..25d846ed7a7bd 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
[ ... ]
> @@ -2121,13 +2103,6 @@ static void at_dma_remove(struct platform_device *pdev)
> struct dma_chan *chan, *_chan;
>
> at_dma_off(atdma);
> - if (pdev->dev.of_node)
> - of_dma_controller_free(pdev->dev.of_node);
> - dma_async_device_unregister(&atdma->dma_device);
> -
> - dma_pool_destroy(atdma->memset_pool);
> - dma_pool_destroy(atdma->lli_pool);
> - free_irq(platform_get_irq(pdev, 0), atdma);
>
> list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels,
> device_node) {
> @@ -2135,8 +2110,6 @@ static void at_dma_remove(struct platform_device *pdev)
> atc_disable_chan_irq(atdma, chan->chan_id);
> list_del(&chan->device_node);
[Severity: High]
Will unlinking the channels here prevent dmaenginem_async_device_unregister()
from cleaning them up?
Because devres handles dmaenginem_async_device_unregister() after
at_dma_remove() returns, the unregister function will iterate over the
now-empty &atdma->dma_device.channels list.
Does this skip the channel unregistration process, leaking the chan->local
per-CPU memory and chan->dev sysfs nodes?
If the sysfs nodes remain, won't reloading the driver fail due to sysfs name
conflicts?
> }
> -
> - clk_disable_unprepare(atdma->clk);
> }
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260723050732.290935-1-rosenp@gmail.com?part=1
prev parent reply other threads:[~2026-07-23 5:16 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-23 5:07 [PATCH] dmaengine: at_hdmac: use more devm in _probe Rosen Penev
2026-07-23 5:16 ` sashiko-bot [this message]
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