Re: [PATCHv2 1/2] dmaengine: idma64: use kzalloc_flex

[Andy Shevchenko]

On Sun, Jul 12, 2026 at 03:00:38PM -0700, Rosen Penev wrote:
> Simplifies allocations by using a flexible array member in this struct.
> 
> Remove idma64_alloc_desc. It now offers no readability advantages in
> this single usage.
> 
> Add __counted_by to get extra runtime analysis.
> 
> Apply the exact same treatment to struct idma64_dma and devm_kzalloc.


...

> static struct dma_async_tx_descriptor *idma64_prep_slave_sg(

>  	struct scatterlist *sg;
>  	unsigned int i;
>  
> -	desc = idma64_alloc_desc(sg_len);
> +	desc = kzalloc_flex(*desc, hw, sg_len, GFP_NOWAIT);
>  	if (!desc)
>  		return NULL;
>  
> +	desc->ndesc = sg_len;

There are two places where this is updated. Are you sure the code become
correct after this change? Perhaps idma64_desc_free() needs additional care?

>  	for_each_sg(sgl, sg, sg_len, i) {
>  		struct idma64_hw_desc *hw = &desc->hw[i];

>  		hw->len = sg_dma_len(sg);
>  	}
>  
> -	desc->ndesc = sg_len;
>  	desc->direction = direction;
>  	desc->status = DMA_IN_PROGRESS;

In case the above is okay to do, move all three up to keep this block of
assignments together.

-- 
With Best Regards,
Andy Shevchenko