Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934413AbZLGA1K (ORCPT ); Sun, 6 Dec 2009 19:27:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932825AbZLGA0e (ORCPT ); Sun, 6 Dec 2009 19:26:34 -0500 Received: from kroah.org ([198.145.64.141]:34458 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758359AbZLGANR (ORCPT ); Sun, 6 Dec 2009 19:13:17 -0500 X-Mailbox-Line: From gregkh@mini.kroah.org Sun Dec 6 16:06:50 2009 Message-Id: <20091207000650.809125417@mini.kroah.org> User-Agent: quilt/0.48-1 Date: Sun, 06 Dec 2009 16:00:36 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Harald Welte , Dave Jones Subject: [060/119] [CPUFREQ] Enable ACPI PDC handshake for VIA/Centaur CPUs References: <20091206235936.208334321@mini.kroah.org> Content-Disposition: inline; filename=enable-acpi-pdc-handshake-for-via-centaur-cpus.patch In-Reply-To: <20091207000938.GA24743@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1792 Lines: 40 2.6.31-stable review patch. If anyone has any objections, please let us know. ------------------ From: Harald Welte commit d77b81974521c82fa6fda38dfff1b491dcc62a32 upstream. In commit 0de51088e6a82bc8413d3ca9e28bbca2788b5b53, we introduced the use of acpi-cpufreq on VIA/Centaur CPU's by removing a vendor check for VENDOR_INTEL. However, as it turns out, at least the Nano CPU's also need the PDC (processor driver capabilities) handshake in order to activate the methods required for acpi-cpufreq. Since arch_acpi_processor_init_pdc() contains another vendor check for Intel, the PDC is not initialized on VIA CPU's. The resulting behavior of a current mainline kernel on such systems is: acpi-cpufreq loads and it indicates CPU frequency changes. However, the CPU stays at a single frequency This trivial patch ensures that init_intel_pdc() is called on Intel and VIA/Centaur CPU's alike. Signed-off-by: Harald Welte Signed-off-by: Dave Jones Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/acpi/processor.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/kernel/acpi/processor.c +++ b/arch/x86/kernel/acpi/processor.c @@ -79,7 +79,8 @@ void arch_acpi_processor_init_pdc(struct struct cpuinfo_x86 *c = &cpu_data(pr->id); pr->pdc = NULL; - if (c->x86_vendor == X86_VENDOR_INTEL) + if (c->x86_vendor == X86_VENDOR_INTEL || + c->x86_vendor == X86_VENDOR_CENTAUR) init_intel_pdc(pr, c); return; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/