From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robert Jarzmik Subject: Re: [PATCH 4/4] dmaengine: pxa_dma: fix the maximum requestor line Date: Mon, 15 Feb 2016 18:24:57 +0100 Message-ID: <87fuwt28eu.fsf@belgarion.home> References: <1455225798-9510-1-git-send-email-robert.jarzmik@free.fr> <1455225798-9510-5-git-send-email-robert.jarzmik@free.fr> <20160215163524.GI19598@localhost> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20160215163524.GI19598@localhost> (Vinod Koul's message of "Mon, 15 Feb 2016 22:05:24 +0530") Sender: linux-kernel-owner@vger.kernel.org To: Vinod Koul Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Daniel Mack , Haojian Zhuang , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dmaengine@vger.kernel.org List-Id: devicetree@vger.kernel.org Vinod Koul 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 ? Cheers.