From patchwork Wed Jun 28 17:07:14 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 9814895 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CF1B360365 for ; Wed, 28 Jun 2017 17:07:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E476D2807B for ; Wed, 28 Jun 2017 17:07:20 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D8AAA28584; Wed, 28 Jun 2017 17:07:20 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0E0E52807B for ; Wed, 28 Jun 2017 17:07:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751492AbdF1RHS (ORCPT ); Wed, 28 Jun 2017 13:07:18 -0400 Received: from foss.arm.com ([217.140.101.70]:46244 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751489AbdF1RHR (ORCPT ); Wed, 28 Jun 2017 13:07:17 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 24093344; Wed, 28 Jun 2017 10:07:17 -0700 (PDT) Received: from [10.1.210.28] (e107155-lin.cambridge.arm.com [10.1.210.28]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9AD1C3F41F; Wed, 28 Jun 2017 10:07:15 -0700 (PDT) Cc: Sudeep Holla , linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, Neil Armstrong , Kevin Hilman Subject: Re: [PATCH] clk: scpi: error when clock fails to register To: Jerome Brunet , Michael Turquette , Stephen Boyd References: <20170628135345.9337-1-jbrunet@baylibre.com> <1498664332.2337.6.camel@baylibre.com> <76efd418-9fd5-6ac5-b4c9-c75c5df69df0@arm.com> <1498668381.2337.10.camel@baylibre.com> From: Sudeep Holla Organization: ARM Message-ID: <3e77fd3c-9807-10d4-3a8c-cab8b5562f6c@arm.com> Date: Wed, 28 Jun 2017 18:07:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.1 MIME-Version: 1.0 In-Reply-To: <1498668381.2337.10.camel@baylibre.com> Content-Language: en-US Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On 28/06/17 17:46, Jerome Brunet wrote: > On Wed, 2017-06-28 at 16:52 +0100, Sudeep Holla wrote: [..] >> >> Thanks for this stack. I just worked out the same path now. I did come >> up with the patch as below. That should work if my understanding is correct. > > I tried. Thanks. > It does not work unfortunately. Still crashes but somewhere else: > [ 2.301482] [] scpi_of_clk_src_get+0x14/0x58 > [ 2.307261] [] __of_clk_get_by_name+0x100/0x118 > [ 2.313297] [] clk_get+0x2c/0x78 > [ 2.318044] [] dev_pm_opp_get_opp_table+0xb0/0x118 > [ 2.324338] [] dev_pm_opp_add+0x20/0x68 > [ 2.329687] [] scpi_init_opp_table+0xa8/0x188 > [ 2.335550] [] _get_cluster_clk_and_freq_table+0x80/0x180 > [ 2.342450] [] bL_cpufreq_init+0x3f0/0x480 > [ 2.348056] [] cpufreq_online+0xc0/0x658 > [ 2.353490] [] cpufreq_add_dev+0x78/0x88 > [ 2.358924] [] subsys_interface_register+0x84/0xc8 > [ 2.365220] [] cpufreq_register_driver+0x138/0x1b8 > [ 2.371516] [] bL_cpufreq_register+0x74/0x120 > [ 2.377381] [] scpi_cpufreq_probe+0x28/0x38 > [ 2.383076] [] platform_drv_probe+0x50/0xb8 > [ 2.388766] [] driver_probe_device+0x21c/0x2d8 > Looks like a different route and I know why. I have added an extra check now which should work if I have not missed anything more. > I have not looked at ALL the clock providers, but I have seen a few and I don't > remember seeing any which fails, at some point, to register a clocks and still > register successfully. > No problem, as I said I am fine with the patch you sent as a fix for now but just curious to know what are the issues to be fixed to continue supporting that feature. Please bear with me. > It seems strange to continue with a broken controller. > I would have agreed if it was single driver or h/w controlled by Linux. Since it's in the firmware, we should allow the working clocks/opps to work though few are broken. It's not good if we had to disable everything if some piece of firmware is not yet ready or broken. But again, we can get it working later, for now, I am fine with you patch. Regards, Sudeep --- @@ -245,11 +245,14 @@ static int scpi_clk_add(struct device *dev, struct device_node *np, sclk->id = val; err = scpi_clk_ops_init(dev, match, sclk, name); - if (err) + if (err) { dev_err(dev, "failed to register clock '%s'\n", name); - else + clk_data->clk[idx] = NULL; + devm_kfree(dev, sclk); + } else { dev_dbg(dev, "Registered clock '%s'\n", name); - clk_data->clk[idx] = sclk; + clk_data->clk[idx] = sclk; + } } return of_clk_add_hw_provider(np, scpi_of_clk_src_get, clk_data); -- To unsubscribe from this list: send the line "unsubscribe linux-clk" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git i/drivers/clk/clk-scpi.c w/drivers/clk/clk-scpi.c index 96d37175d0ad..a0b9b4c84be3 100644 --- i/drivers/clk/clk-scpi.c +++ w/drivers/clk/clk-scpi.c @@ -192,7 +192,7 @@ scpi_of_clk_src_get(struct of_phandle_args *clkspec, void *data) for (count = 0; count < clk_data->clk_num; count++) { sclk = clk_data->clk[count]; - if (idx == sclk->id) + if (sclk && idx == sclk->id) return &sclk->hw; }