Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752718AbdLHRE4 (ORCPT ); Fri, 8 Dec 2017 12:04:56 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:56210 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750777AbdLHREw (ORCPT ); Fri, 8 Dec 2017 12:04:52 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 609776071B Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=sboyd@codeaurora.org Date: Fri, 8 Dec 2017 09:04:49 -0800 From: Stephen Boyd To: Loys Ollivier Cc: Jerome Forissier , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, David Brown , Andy Gross , linux-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jerome Brunet , Jens Wiklander Subject: Re: [PATCH v2] firmware: qcom: scm: Fix incorrect of_node_put call in scm_init Message-ID: <20171208170449.GD4283@codeaurora.org> References: <1512555692-14439-1-git-send-email-lollivier@baylibre.com> <20171206200601.GH4283@codeaurora.org> <40113581-4b8c-defe-ba90-0aabc30a1b6d@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1705 Lines: 44 On 12/07, Loys Ollivier wrote: > > > On 07/12/2017 09:42, Jerome Forissier wrote: > > > > > > On 12/06/2017 09:06 PM, Stephen Boyd wrote: > >> On 12/06, Loys Ollivier wrote: > >>> When using other platform architectures, in the init of the qcom_scm > >>> driver, of_node_put is called on /firmware if no qcom dt is found. > >>> This results in a kernel error: Bad of_node_put() on /firmware. > >>> > >>> The call to of_node_put from the qcom_scm init is unnecessary as > >>> of_find_matching_node is calling it automatically. > >>> > >>> Remove this of_node_put(). > >>> > >>> Fixes: d0f6fa7ba2d6 ("firmware: qcom: scm: Convert SCM to platform driver") > >>> Signed-off-by: Loys Ollivier > >>> --- > >> > >> This still looks wrong. Especially if of_find_matching_node() is > >> going to look for siblings of the /firmware node for the > >> compatible string for scm device. Why do we check at all? Can't > >> we just delete this and let of_platform_populate() take care of > >> it? BTW, OP-TEE driver seems to have a similar problem. > > > > https://lkml.org/lkml/2017/11/29/230 > > > Well, the patch I sent is a fix for a specific bug I am encountering. > I tested the patch and it solves my problem. Stephen, your changes looks > good but it's a change in the driver's behavior. Maybe it could be > another patch ? Sure. But there's another of_node_put(fw_np) in this function, so why isn't that also removed? Assuming of_find_matching_node() is calling of_node_put() on what's passed in, then the node is going to get put twice in the "working" case. Andy? -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project