From patchwork Fri Sep 7 02:58:49 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shawn Guo X-Patchwork-Id: 1418841 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id D3690DFFCF for ; Fri, 7 Sep 2012 03:00:56 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1T9omE-0005sa-PE; Fri, 07 Sep 2012 02:58:38 +0000 Received: from mail-pb0-f49.google.com ([209.85.160.49]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1T9omD-0005sC-3H for linux-arm-kernel@lists.infradead.org; Fri, 07 Sep 2012 02:58:37 +0000 Received: by pbbrq8 with SMTP id rq8so3454501pbb.36 for ; Thu, 06 Sep 2012 19:58:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent :x-gm-message-state; bh=aDdmIEpyCRXJH4Wpz7/5581zLxvSLAqbuUQ2TPUJrfw=; b=LCQQIiTQYQZQiBoexntm2yhsjdbPRwSvgQngFqmDBDUy/pO5DYJSkZmW4rGF62A1kD wSnb6gk1/kTGkjkPnHwcGgC8TD5CkIr8GXqEcX5Dd+KpTnrkbTL4vx9SvVwP1Zh1vmvk pLGZ8qHtwULbdbDxggbJ+6NlXxsI83Dd14U6S+2WZpFcwbLMu3PAfF0PFHiP5b5lj+qk U14QiOswY+KiwH+cF7862fD6EyAd+UD4gtOMk3vOmoAatwyogMKG8qmt6wNhZ7eJgZVT 3DdHU/pyv+9Xp8UXvGxjMcqqr5Y5glQUkpN+sHjQAerX7kH1mmdJOwGlK1q1SW7T1frV Zd6A== Received: by 10.66.79.36 with SMTP id g4mr6453069pax.67.1346986715947; Thu, 06 Sep 2012 19:58:35 -0700 (PDT) Received: from S2101-09.ap.freescale.net ([221.225.141.144]) by mx.google.com with ESMTPS id qo8sm2373072pbb.19.2012.09.06.19.58.31 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 06 Sep 2012 19:58:35 -0700 (PDT) Date: Fri, 7 Sep 2012 10:58:49 +0800 From: Shawn Guo To: Stephen Warren Subject: Re: [PATCH v3 1/3] ARM: add cpufreq transiton notifier to adjust loops_per_jiffy for smp Message-ID: <20120907025847.GI26709@S2101-09.ap.freescale.net> References: <1344577046-14847-1-git-send-email-shawn.guo@linaro.org> <1344577046-14847-2-git-send-email-shawn.guo@linaro.org> <5049252D.9000802@wwwdotorg.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <5049252D.9000802@wwwdotorg.org> User-Agent: Mutt/1.5.21 (2010-09-15) X-Gm-Message-State: ALoCoQnsfBtiOPittlDkofcIjUW66zVYKxOHsTLR4R5o1RoRqwf5WkbVSnzvi5CJX4LH6hGKM6tH X-Spam-Note: CRM114 invocation failed X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.160.49 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Kevin Hilman , Nishanth Menon , Mike Turquette , Richard Zhao , linux-pm@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, Mark Brown , cpufreq@vger.kernel.org, "Rafael J. Wysocki" , Shilimkar Santosh , Rob Herring , "linux-tegra@vger.kernel.org" , Russell King - ARM Linux , Richard Zhao , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org On Thu, Sep 06, 2012 at 04:35:25PM -0600, Stephen Warren wrote: > I believe this patch is causing issues initializing PCI-Express on Tegra. > > In next-20120906, I cold-booted 10 times. 3 times, PCIe initialized OK, > and 7 times, the driver timed out in arch/arm/mach-tegra/pcie.c function > tegra_pcie_check_link(). With this patch reverted, another 10 cold boot > attempts all succeeded just fine. Similarly, the regression appeared in > next-20120905, and I isolated it to arch/arm/kernel/, and this is the > only patch in that directory between next-20120904 and next-20120905. > > Do you have any idea what the problem might be? > > Looking at the timestamps in dmesg in the failing case, the driver is > waiting the expected (per pcie.c driver code) 1.2 seconds before giving > up on the port, although I suppose if the kernel's idea of real-time is > off, then the dmesg log timestamps might be off too. Just for identifying the problem, can you test the following change to see if it fixes the failure. Regards, Shawn diff --git a/arch/arm/mach-tegra/cpu-tegra.c b/arch/arm/mach-tegra/cpu-tegra.c index ceb52db..a3bbdc9 100644 --- a/arch/arm/mach-tegra/cpu-tegra.c +++ b/arch/arm/mach-tegra/cpu-tegra.c @@ -247,5 +247,5 @@ static void __exit tegra_cpufreq_exit(void) MODULE_AUTHOR("Colin Cross "); MODULE_DESCRIPTION("cpufreq driver for Nvidia Tegra2"); MODULE_LICENSE("GPL"); -module_init(tegra_cpufreq_init); +late_init(tegra_cpufreq_init); module_exit(tegra_cpufreq_exit);