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Date: Mon, 15 Feb 2016 23:03:00 +0530
From: Vinod Koul <vinod.koul@intel.com>
To: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Ian Campbell <ijc+devicetree@hellion.org.uk>,
        Kumar Gala <galak@codeaurora.org>, Daniel Mack <daniel@zonque.org>,
        Haojian Zhuang <haojian.zhuang@gmail.com>, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        dmaengine@vger.kernel.org
Subject: Re: [PATCH 4/4] dmaengine: pxa_dma: fix the maximum requestor line
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On Mon, Feb 15, 2016 at 06:24:57PM +0100, Robert Jarzmik wrote:
> Vinod Koul <vinod.koul@intel.com> writes:
> 
> > On Thu, Feb 11, 2016 at 10:23:18PM +0100, Robert Jarzmik wrote:
> >> @@ -1399,13 +1405,17 @@ static int pxad_probe(struct platform_device *op)
> >>  		return PTR_ERR(pdev->base);
> >>  
> >>  	of_id = of_match_device(pxad_dt_ids, &op->dev);
> >> -	if (of_id)
> >> +	if (of_id) {
> >>  		of_property_read_u32(op->dev.of_node, "#dma-channels",
> >>  				     &dma_channels);
> >> -	else if (pdata && pdata->dma_channels)
> >> +		of_property_read_u32(op->dev.of_node, "#requestors",
> >> +				     &nb_requestors);
> >
> > I think we should check the return value here. This might be err in case
> > when we have older DT on platform, but still should work with default in
> > that case
> 
> Okay, but how should the code react to the err case, more specifically to
> -EINVAL or -ENODATA ? As this property is optional as per the device-tree
> description, the current code leaves nb_requestors = 0, as is specified in the
> description, and fits the mmp_pdma case.
> 
> What do you think should be done ? A warning message ? Something else ?

Message is fine, but in order for not to regress we should set this to 32
(IIRC default before this, right) and not zero.

-- 
~Vinod