From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 20CE6ECE588 for ; Tue, 15 Oct 2019 16:18:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F01AF2064A for ; Tue, 15 Oct 2019 16:18:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387838AbfJOQSF (ORCPT ); Tue, 15 Oct 2019 12:18:05 -0400 Received: from foss.arm.com ([217.140.110.172]:42276 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387829AbfJOQSF (ORCPT ); Tue, 15 Oct 2019 12:18:05 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4A97F337; Tue, 15 Oct 2019 09:18:05 -0700 (PDT) Received: from bogus (e107155-lin.cambridge.arm.com [10.1.196.42]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 984D73F68E; Tue, 15 Oct 2019 09:18:04 -0700 (PDT) Date: Tue, 15 Oct 2019 17:17:59 +0100 From: Sudeep Holla To: "Rafael J. Wysocki" Cc: Viresh Kumar , "linux-pm@vger.kernel.org" , Sudeep Holla Subject: Re: NULL pointer dereference in cpufreq_set_policy Message-ID: <20191015161759.GA16693@bogus> References: <20191015155735.GA29105@bogus> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Tue, Oct 15, 2019 at 06:08:14PM +0200, Rafael J. Wysocki wrote: > On Tue, Oct 15, 2019 at 5:57 PM Sudeep Holla wrote: > > > > Hi Viresh, > > > > I was trying to unify Vexpress SPC driver and arm_big_little generic > > driver as it's the only user of bL driver and switcher in the mainline. > > I did this a while ago(v5.3) and encountered the kernel crash with NULL > > pointer reference(crash log with some debug enabled below). > > > > Since dev_pm_qos_* was added in v5.3 with the Commit 18c49926c4bf > > ("cpufreq: Add QoS requests for userspace constraints"), I just tried > > reverting that and it fixed the crash. I haven't spent much time > > debugging, since it has been for a while I wanted to report it. > > This looks like another manifestation of the bug discussed here: > https://lore.kernel.org/linux-pm/5ad2624194baa2f53acc1f1e627eb7684c577a19.1562210705.git.viresh.kumar@linaro.org/T/#md2d89e95906b8c91c15f582146173dce2e86e99f Indeed, it reminded me to dig up the setup, try again and report this bug before I forget again about the issue as this platform is in back burner and not priority :) -- Regards, Sudeep