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Date: Thu, 25 Apr 2024 14:34:13 +0530
From: Vinod Koul <vkoul@kernel.org>
To: Frank Li <Frank.li@nxp.com>
Cc: Ma Ke <make_ruc2021@163.com>, shawnguo@kernel.org,
	s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com,
	dmaengine@vger.kernel.org, imx@lists.linux.dev,
	linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] dmaengine: mxs-dma: Add check for dma_set_max_seg_size()
Message-ID: <ZiocjS6tbeTt2mPD@matsya>
References: <20240423143205.1420976-1-make_ruc2021@163.com>
 <ZiiFZZ8kwDeRWhjR@lizhi-Precision-Tower-5810>
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On 24-04-24, 00:07, Frank Li wrote:
> On Tue, Apr 23, 2024 at 10:32:05PM +0800, Ma Ke wrote:

> > -	dma_set_max_seg_size(mxs_dma->dma_device.dev, MAX_XFER_BYTES);
> > +	ret = dma_set_max_seg_size(mxs_dma->dma_device.dev, MAX_XFER_BYTES);
> > +	if (ret)
> > +		return ret;
> 
> How error happen? 
> 
> static inline int dma_set_max_seg_size(struct device *dev, unsigned int size)
> {
> 	if (dev->dma_parms) {
> 		dev->dma_parms->max_segment_size = size;
> 		return 0;
> 	}
> 	return -EIO;
> }
> 
> Only possible dev->dma_parms is null. but mxs-dma is platform device, it
> point to platform's dma_parms field. Look like impossible it is null.

Yep, checking for the sake of checking is bad. It needs to be logical

-- 
~Vinod