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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8A8B6C7EE23 for ; Wed, 10 May 2023 00:08:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229785AbjEJAIY (ORCPT ); Tue, 9 May 2023 20:08:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35874 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229527AbjEJAIX (ORCPT ); Tue, 9 May 2023 20:08:23 -0400 X-Greylist: delayed 488 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 09 May 2023 17:08:22 PDT Received: from vulcan.kevinlocke.name (vulcan.kevinlocke.name [107.191.43.88]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 864E5273D; Tue, 9 May 2023 17:08:22 -0700 (PDT) Received: from kevinolos.kevinlocke.name (071-015-196-093.res.spectrum.com [71.15.196.93]) (Authenticated sender: kevin@kevinlocke.name) by vulcan.kevinlocke.name (Postfix) with ESMTPSA id DD959395E4EB; Wed, 10 May 2023 00:00:10 +0000 (UTC) Received: by kevinolos.kevinlocke.name (Postfix, from userid 1000) id AC700130072A; Tue, 9 May 2023 18:00:07 -0600 (MDT) Date: Tue, 9 May 2023 18:00:07 -0600 From: Kevin Locke To: Petr Pavlu Cc: rafael@kernel.org, lenb@kernel.org, viresh.kumar@linaro.org, pmladek@suse.com, mcgrof@kernel.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4] ACPI: cpufreq: use a platform device to load ACPI PPC and PCC drivers Message-ID: Mail-Followup-To: Petr Pavlu , rafael@kernel.org, lenb@kernel.org, viresh.kumar@linaro.org, pmladek@suse.com, mcgrof@kernel.org, linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org References: <20230316151036.10181-1-petr.pavlu@suse.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230316151036.10181-1-petr.pavlu@suse.com> Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On Thu, 2023-03-16 at 16:10 +0100, Petr Pavlu wrote: > The patch extends the ACPI parsing logic to check the ACPI namespace if > the PPC or PCC interface is present and creates a virtual platform > device for each if it is available. The acpi-cpufreq and pcc-cpufreq > drivers are then updated to map to these devices. > > This allows to try loading acpi-cpufreq and pcc-cpufreq only once during > boot and only if a given interface is available in the firmware. As a result of this patch (691a637123470bfe63bccf5836ead40fac4c7fab) my ThinkPad T430 with an i5-3320M CPU configured with CONFIG_X86_INTEL_PSTATE=y and CONFIG_X86_ACPI_CPUFREQ=m (Debian's amd64 kernel config) now logs kernel: acpi-cpufreq: probe of acpi-cpufreq failed with error -17 during boot. Presumably this occurs because loading acpi-cpufreq returns -EEXIST when intel-pstate is already loaded (or built-in, as in this case). I'm unsure why the message was not printed before; perhaps a difference between driver probing for platform and cpu bus types? Although the error message is not wrong, it may lead to unnecessary investigation by sysadmins, as it did for me. I thought it was worth reporting so you can consider whether the change is desirable. Cheers, Kevin