[PATCH 00/59] dma: Convert to platform remove callback returning void

Vinod Koul vkoul at kernel.org
Thu Sep 28 17:49:13 AEST 2023

On 19-09-23, 15:31, Uwe Kleine-König wrote:
> Hello,
> this series convert nearly all platform drivers below drivers/dma to use
> .remove_new(). The motivation is to get rid of an integer return code
> that is (mostly) ignored by the platform driver core and error prone on
> the driver side.

I have applied this, with change of subsystem to dmaengine: xxx
> See commit 5c5a7680e67b ("platform: Provide a remove callback that
> returns no value") for an extended explanation and the eventual goal.
> There are 4 drivers I didn't convert in this series:
> 	drivers/dma/milbeaut-hdmac.c
> 	drivers/dma/milbeaut-xdmac.c
> 	drivers/dma/uniphier-mdmac.c
> 	drivers/dma/uniphier-xdmac.c
> These all might return early in .remove() if dmaengine_terminate_sync()
> fails. I only looked deeper into the first one, and this shows exactly
> the error that is easy to make with .remove() returning an int: When
> returning early from .remove(), some cleanup (here:
> dma_async_device_unregister()) is skipped. So the dma device stays
> known, but the device is still unregistered and the devm allocated stuff
> (here e.g. *mdev) is freed. So it can probably easily happen, that
> something tries to use the dma device and this will likely result in an
> oops.

We should convert these too, thanks for your work for the conversion


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