linux-kernel - Re: [PATCH v2 2/3] dmaengine: Use device_match_of

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Message-ID: <aRG8cVly3b7sR9Vw@u67f9ca6e60d851.ant.amazon.com>
Date: Mon, 10 Nov 2025 11:20:33 +0100
From: Praveen Kumar <kpraveen.lkml@...il.com>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Cc: dmaengine@...r.kernel.org, linux-kernel@...r.kernel.org,
	Vinod Koul <vkoul@...nel.org>
Subject: Re: [PATCH v2 2/3] dmaengine: Use device_match_of_node() helper

On Mon, Nov 10, 2025 at 09:47:44AM +0100, Andy Shevchenko wrote:
> Instead of open coding, use device_match_of_node() helper.
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
> ---
>  drivers/dma/dmaengine.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
> index eb27a72cd4c5..e89280587d5d 100644
> --- a/drivers/dma/dmaengine.c
> +++ b/drivers/dma/dmaengine.c
> @@ -765,7 +765,7 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
>  	mutex_lock(&dma_list_mutex);
>  	list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
>  		/* Finds a DMA controller with matching device node */
> -		if (np && device->dev->of_node && np != device->dev->of_node)
> +		if (np && !device_match_of_node(device->dev, np))

I see a difference in what device_match_of_node does vs what was
happening in the previous check. And, we have an unwanted double
check of np.

int device_match_of_node(struct device *dev, const void *np)
{
        return np && dev->of_node == np;
}

Instead, I would recommend,

        if (device->dev->of_node && !device_match_of_node(device->dev, np))
                continue;

Regards,
Praveen Kumar.

>  			continue;
>  
>  		chan = find_candidate(device, mask, fn, fn_param);
> -- 
> 2.50.1
>