Re: [PATCH 1/2] dmaengine: add dmaengine_prep_slave_sg_context() to wrap prep_slave_sg

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [Medium] dmaengine: missing NULL pointer checks in dmaengine_prep_slave_sg_context()
- [Low] dmaengine: missing __deprecated attribute on dmaengine_prep_slave_sg_context()
- [Low] dmaengine: typo 'Depercated' in API comment
--

commit 624ba4c53934aaa9d35d6692c60ed829474f761a
Author: Frank Li <Frank.Li@nxp.com>

dmaengine: add dmaengine_prep_slave_sg_context() to wrap prep_slave_sg

This adds a wrapper function for dmaengine_prep_slave_sg_context() to allow
certain consumers and providers to use the context argument without accessing
the DMA engine callback pointer directly. It also prepares to make the DMA
engine provider internals private, and marks the new wrapper as deprecated.

> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> index c3a49a33307c6..b4589cad6d742 100644
> --- a/include/linux/dmaengine.h
> +++ b/include/linux/dmaengine.h
> @@ -1084,6 +1084,19 @@ dmaengine_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
>  	return dmaengine_prep_config_sg(chan, sgl, sg_len, dir, flags, NULL);
>  }
>  
> +/* Depercated, don't use it except sound/soc/sprd/ */

[Severity: Low]
This isn't a bug, but there's a typo in the comment: "Depercated" instead of
"Deprecated".

> +static inline struct dma_async_tx_descriptor *

[Severity: Low]
Since the comment and commit message note this function is deprecated, should
it be marked with the __deprecated compiler attribute so that any new usages
trigger a compile-time warning?

> +dmaengine_prep_slave_sg_context(struct dma_chan *chan, struct scatterlist *sgl,
> +				unsigned int sg_len, enum dma_transfer_direction dir,
> +				unsigned long flags, void *context)
> +{
> +	if (!chan->device->device_prep_slave_sg)

[Severity: Medium]
Does this expose callers to a NULL pointer dereference if an uninitialized
or invalid channel is passed?

Other public wrappers in the DMA engine API, such as dmaengine_prep_config_sg(),
explicitly check if (!chan || !chan->device) before accessing the device
pointer.

Should this function include the same safeguard?

> +		return NULL;
> +
> +	return chan->device->device_prep_slave_sg(chan, sgl, sg_len, dir,
> +						  flags, context);
> +}

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260917-b4-dmaengine-prep-slave-sg-v1-0-239c12864143@nxp.com?part=1