From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Garrett Subject: Re: [patch 1/3] acpi: check _PSS invalidation when BIOS report _PSS with 0x80000000 Date: Mon, 25 May 2009 12:01:52 +0100 Message-ID: <20090525110152.GA31474@srcf.ucam.org> References: <200905122054.n4CKsfa3001669@imap1.linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from cavan.codon.org.uk ([93.93.128.6]:40709 "EHLO vavatch.codon.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751375AbZEYLCE (ORCPT ); Mon, 25 May 2009 07:02:04 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Len Brown Cc: akpm@linux-foundation.org, linux-acpi@vger.kernel.org, youquan.song@intel.com, venkatesh.pallipadi@intel.com On Thu, May 14, 2009 at 01:35:10PM -0400, Len Brown wrote: > NAK > > This is a recording. > > Andrew, please remove this patch from your series > per issues earlier discussed on the list. On the dump I have from a machine showing this issue, we'd fail gracefully if we checked the return value of acpi_processor_preregister_performance() as the coordination type is set to an invalid value. Are there any cases where this fails and the hardware still works? If not, then: diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c index 208ecf6..fbb8e59 100644 --- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c +++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -561,7 +561,11 @@ static int __init acpi_cpufreq_early_init(void) } /* Do initialization in ACPI core */ - acpi_processor_preregister_performance(acpi_perf_data); + if (acpi_processor_preregister_performance(acpi_perf_data)) { + free_acpi_perf_data(); + return -EINVAL; + } + return 0; } would seem to be correct. The alternative is that the number of processors is also set to 0x80000000 - according to the spec "OSPM will not start performing power state transitions to a particular P-state until this number of processors belonging to the same domain have been detected and started". Since we're clearly never reaching that condition, why is the governor even getting started? -- Matthew Garrett | mjg59@srcf.ucam.org