[PATCH] dmaengine: dw-edma: Clear chip->dw after removal

[PATCH] dmaengine: dw-edma: Clear chip->dw after removal

[Koichiro Den]

dw_edma_remove() unregisters the DMA device and releases its resources,
but leaves chip->dw set, so the pointer no longer indicates whether the
eDMA instance is still registered. Some in-tree glue drivers call
dw_pcie_ep_deinit() when dw_pcie_ep_init_registers() fails. If
initialization has already removed eDMA, deinitialization attempts to
tear down the same instance again.

Regardless of whether those error paths are reworked, clear chip->dw on
removal to match its assignment on successful probe. This also lets the
existing NULL check skip repeated teardown.

Fixes: 869bc5253406 ("PCI: dwc: ep: Fix DBI access failure for drivers requiring refclk from host")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20261022082230.3164834-1-den@valinux.co.jp?part=2
Signed-off-by: Koichiro Den <den@valinux.co.jp>
---
 drivers/dma/dw-edma/dw-edma-core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index d682074eaa0e..daa2084485d5 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -1509,6 +1509,8 @@ int dw_edma_remove(struct dw_edma_chip *chip)
 		list_del(&chan->vc.chan.device_node);
 	}
 
+	chip->dw = NULL;
+
 	return err;
 }
 EXPORT_SYMBOL_GPL(dw_edma_remove);

base-commit: 7475ea8b58616b33c04afb976cf0fbaad9dd63fb
-- 
2.54.0

Re: [PATCH] dmaengine: dw-edma: Clear chip->dw after removal

[Frank Li]

On Tue, Nov 10, 2026 at 05:24:33PM +0900, Koichiro Den wrote:
> dw_edma_remove() unregisters the DMA device and releases its resources,
> but leaves chip->dw set, so the pointer no longer indicates whether the
> eDMA instance is still registered. Some in-tree glue drivers call
> dw_pcie_ep_deinit() when dw_pcie_ep_init_registers() fails. If
> initialization has already removed eDMA, deinitialization attempts to
> tear down the same instance again.
>
> Regardless of whether those error paths are reworked, clear chip->dw on
> removal to match its assignment on successful probe. This also lets the
> existing NULL check skip repeated teardown.
>
> Fixes: 869bc5253406 ("PCI: dwc: ep: Fix DBI access failure for drivers requiring refclk from host")
> Reported-by: Sashiko <sashiko-bot@kernel.org>
> Closes: https://sashiko.dev/#/patchset/20261022082230.3164834-1-den@valinux.co.jp?part=2
> Signed-off-by: Koichiro Den <den@valinux.co.jp>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/dma/dw-edma/dw-edma-core.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
> index d682074eaa0e..daa2084485d5 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-core.c
> @@ -1509,6 +1509,8 @@ int dw_edma_remove(struct dw_edma_chip *chip)
>  		list_del(&chan->vc.chan.device_node);
>  	}
>
> +	chip->dw = NULL;
> +
>  	return err;
>  }
>  EXPORT_SYMBOL_GPL(dw_edma_remove);
>
> base-commit: 7475ea8b58616b33c04afb976cf0fbaad9dd63fb
> --
> 2.54.0
>