Re: [PATCH v2 05/13] dmaengine: ste_dma40: Fix LCLA allocation order

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] DMA_CYCLIC capability applied to wrong dma_device during initialization.
--

--- Patch [5]: [PATCH v2 05/13] dmaengine: ste_dma40: Fix LCLA allocation order ---
commit d327ef86f7f30a5a539d2fef537e53e5f0f2dc5f
Author: Linus Walleij <linusw@kernel.org>

dmaengine: ste_dma40: Fix LCLA allocation order

This commit modifies d40_lcla_allocate() to use get_order() to determine
the page allocation order, instead of directly passing the calculated
number of pages to __get_free_pages() and free_pages().

Closes: https://lore.kernel.org/dmaengine/20260819225114.AE1511F000E9@smtp.kernel.org/

> diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
> index 384c2f3805b02..804eb5eab06b4 100644
> --- a/drivers/dma/ste_dma40.c
> +++ b/drivers/dma/ste_dma40.c
[ ... ]
> @@ -3670,7 +3669,7 @@ static int __init d40_probe(struct platform_device *pdev)
>  
>  	if (!base->lcla_pool.base_unaligned && base->lcla_pool.base)
>  		free_pages((unsigned long)base->lcla_pool.base,
> -			   base->lcla_pool.pages);
> +			   base->lcla_pool.alloc_order);
>  
>  	kfree(base->lcla_pool.base_unaligned);
>  

[Severity: High]
This is a pre-existing issue, but I noticed a potential problem in
d40_dmaengine_init():

drivers/dma/ste_dma40.c:d40_dmaengine_init() {
    ...
	d40_chan_init(base, &base->dma_both, base->phy_chans,
		      0, num_reserved_chans);

	dma_cap_zero(base->dma_both.cap_mask);
	dma_cap_set(DMA_SLAVE, base->dma_both.cap_mask);
	dma_cap_set(DMA_MEMCPY, base->dma_both.cap_mask);
	dma_cap_set(DMA_CYCLIC, base->dma_slave.cap_mask);
    ...
}

Does this code apply the DMA_CYCLIC capability to the wrong dma_device during
initialization?

By setting DMA_CYCLIC on base->dma_slave.cap_mask instead of
base->dma_both.cap_mask, the dma_both device seems to lack this capability.

Will this cause initialization failures for peripherals requesting a cyclic
channel from dma_both?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260820-dma40-fixes-v2-0-63238334c707@kernel.org?part=5