From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264500AbUHJL7w (ORCPT ); Tue, 10 Aug 2004 07:59:52 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264503AbUHJL7w (ORCPT ); Tue, 10 Aug 2004 07:59:52 -0400 Received: from gort.metaparadigm.com ([203.117.131.12]:49361 "EHLO gort.metaparadigm.com") by vger.kernel.org with ESMTP id S264500AbUHJL6v (ORCPT ); Tue, 10 Aug 2004 07:58:51 -0400 Message-ID: <4118B88A.9090300@metaparadigm.com> Date: Tue, 10 Aug 2004 19:59:06 +0800 From: Michael Clark Organization: Metaparadigm Pte Ltd User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.1) Gecko/20040802 Debian/1.7.1-5 X-Accept-Language: en MIME-Version: 1.0 To: Dave Jones , jeremy@goop.org Cc: Linux Kernel Subject: Re: [PATCH] - Initial dothan speedstep support References: <41131120.5060202@metaparadigm.com> <411365C9.5020909@metaparadigm.com> <20040809142819.GD21238@redhat.com> In-Reply-To: <20040809142819.GD21238@redhat.com> Content-Type: multipart/mixed; boundary="------------000605030803090805050902" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is a multi-part message in MIME format. --------------000605030803090805050902 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Hi Dave, Jeremy, I thought i'd give the ACPI code in speedstep-centrino a try as I wanted to see what the BIOS freq/voltage tables the vendor was using due to the apparent choice of voltages (VID#A through VID#C) in the processor specs. Anyway this is what I found (with the debug code in attached patch): centrino_cpu_init_acpi: 1800000000 Hz, 1340e-03 volts centrino_cpu_init_acpi: 1600000000 Hz, 1292e-03 volts centrino_cpu_init_acpi: 1400000000 Hz, 1228e-03 volts centrino_cpu_init_acpi: 1200000000 Hz, 1164e-03 volts centrino_cpu_init_acpi: 1000000000 Hz, 1116e-03 volts centrino_cpu_init_acpi: 800000000 Hz, 1052e-03 volts centrino_cpu_init_acpi: 600000000 Hz, 988e-03 volts It appears the T42 is using the VID#A voltages (the highest) and my patch was using VID#C (the 2nd from lowest) for which the upper voltage has the biggest difference being 0.032 volts lower - not much in it. As I said earlier in my reading of the specs there seemed to be no guidance on which profile to use aside from the voltage and ripple tolerance tables. So the attached patch (in addition to ACPI freq table debug message) changes the table version to use the VID#A voltage so as to err on the conservative side of a higher voltage (as the upper voltage max for the chip is 1.6v) to allow for cases where the error on the voltage would drop it too low - not sure if just IBM are using this. Would be interesting to see the ACPI freq/voltage tables for other vendor's Dothan laptops. Not sure on whether we should do this although it means we match at least what one vendor has done? Any ideas? (debug printk may be useful for those with ACPI and speedstep for debugging incorrect BIOS tables). Thanks ~mc --------------000605030803090805050902 Content-Type: application/octect-stream; name="cpufreq-speedstep-dothan-VidA.patch" Content-Transfer-Encoding: base64 Content-Disposition: inline; filename="cpufreq-speedstep-dothan-VidA.patch" LS0tIGxpbnV4LTIuNi44LXJjMy1tbTEvYXJjaC9pMzg2L2tlcm5lbC9jcHUvY3B1ZnJlcS9z cGVlZHN0ZXAtY2VudHJpbm8uYy50bXAJMjAwNC0wOC0xMCAxOToyMjo0Ny4wMDAwMDAwMDAg KzA4MDAKKysrIGxpbnV4LTIuNi44LXJjMy1tbTEvYXJjaC9pMzg2L2tlcm5lbC9jcHUvY3B1 ZnJlcS9zcGVlZHN0ZXAtY2VudHJpbm8uYwkyMDA0LTA4LTEwIDE5OjIyOjUzLjAwMDAwMDAw MCArMDgwMApAQCAtMjA2LDcgKzIwNiw3IEBACiAjZGVmaW5lIE9QKG1oeiwgbXZhLCBtdmIs IG12YywgbXZkKQkJCQkJXAogCXsJCQkJCQkJCVwKIAkJLmZyZXF1ZW5jeSA9IChtaHopICog MTAwMCwJCQkJXAotCQkuaW5kZXggPSAoKChtaHopLzEwMCkgPDwgOCkgfCAoKG12YyAtIDcw MCkgLyAxNikgICAgICAgCVwKKwkJLmluZGV4ID0gKCgobWh6KS8xMDApIDw8IDgpIHwgKCht dmEgLSA3MDApIC8gMTYpICAgICAgIAlcCiAJfQogCiAvKiBJbnRlbCBQZW50aXVtIE0gcHJv Y2Vzc29yIDcxNSAvIDEuNTBHSHogKERvdGhhbikgKi8KQEAgLTQ5Myw2ICs0OTMsMTAgQEAK ICAgICAgICAgZm9yIChpPTA7IGk8cC5zdGF0ZV9jb3VudDsgaSsrKSB7CiAJCWNlbnRyaW5v X21vZGVsLT5vcF9wb2ludHNbaV0uaW5kZXggPSBwLnN0YXRlc1tpXS5jb250cm9sOwogCQlj ZW50cmlub19tb2RlbC0+b3BfcG9pbnRzW2ldLmZyZXF1ZW5jeSA9IHAuc3RhdGVzW2ldLmNv cmVfZnJlcXVlbmN5ICogMTAwMDsKKwkJcHJpbnRrKEtFUk5fREVCVUcgImNlbnRyaW5vX2Nw dV9pbml0X2FjcGk6ICIKKwkJICAgICAgICIlZCBIeiwgJWRlLTAzIHZvbHRzXG4iLCAKKwkJ ICAgICAgIGNlbnRyaW5vX21vZGVsLT5vcF9wb2ludHNbaV0uZnJlcXVlbmN5ICogMTAwMCwK KwkJICAgICAgIChjZW50cmlub19tb2RlbC0+b3BfcG9pbnRzW2ldLmluZGV4ICYgMHhmZikg KiAxNiArIDcwMCk7CiAJfQogCWNlbnRyaW5vX21vZGVsLT5vcF9wb2ludHNbcC5zdGF0ZV9j b3VudF0uZnJlcXVlbmN5ID0gQ1BVRlJFUV9UQUJMRV9FTkQ7CiAK --------------000605030803090805050902--