From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: linux-next: Tree for Sept 6 (does not boot on AMD64) Date: Thu, 6 Sep 2012 23:17:52 +0200 Message-ID: <201209062317.53214.rjw@sisk.pl> References: <50490C9D.1070509@amd.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: sedat.dilek@gmail.com Cc: Andre Przywara , Stephen Rothwell , linux-next@vger.kernel.org, LKML , Matthew Garrett , Linux PM list , Thomas Renninger List-Id: linux-next.vger.kernel.org On Thursday, September 06, 2012, Sedat Dilek wrote: > On Thu, Sep 6, 2012 at 10:50 PM, Andre Przywara wrote: > > On 09/06/2012 10:30 PM, Sedat Dilek wrote: > >> > >> On Thu, Sep 6, 2012 at 10:08 PM, Rafael J. Wysocki wrote: > >>> > >>> On Thursday, September 06, 2012, Sedat Dilek wrote: > >>>> > >>>> On Thu, Sep 6, 2012 at 1:48 PM, Sedat Dilek > >>>> wrote: > >>>>> > >>>>> On Thu, Sep 6, 2012 at 9:23 AM, Stephen Rothwell > >>>>> wrote: > >>>>>> > >>>>>> Hi all, > >>>>> > >>>>> Hi, > >>>>> > >>>>> > >>>>> Unfortunately, today's linux-next does not boot here on Ubuntu/precise > >>>>> AMD64. > >>>>> My yesterday's next-20120905 is fine. > >>>>> > >>>>> I throw out all my additional patches an rebuild again as "-2", but > >>>>> this linux-image does not boot. > >>>>> It's in very early stage. > >>>>> I removed "quiet" etc. from kernel-command-line, but this reveals not > >>>>> much more. > >>>>> > >>>>> From the attached kernel-config.diff: > >>>>> Dunno why the 2nd is disabled now and try to turn off the 1st one in a > >>>>> "-3" build. > >>>>> > >>>>> +CONFIG_X86_ACPI_CPUFREQ_CPB=y > >>>>> -CONFIG_USB_LIBUSUAL=y > >>>>> > >>>> > >>>> [ CC Rafael (cpufreq sub-maintainer) ] > >>> > >>> > >>> Well, this is related to the AMD cpufreq patchset I've just added to > >>> linux-next. I'll drop it for now until the issue is resolved. > >>> > >> > >> Hi Rafael, > >> > >> The problem was caused by the slab/next merge (see [1]). > >> > >> [1] http://marc.info/?t=134695686500008&r=1&w=2 > >> > >>>> I hacked to turn off CONFIG_X86_ACPI_CPUFREQ_CPB, but this is not the > >>>> root cause. > >>>> Not sure why this setting is default YES, Rafael? > >>>> > >>>> To switch from upstart to systemd does not help. > >>> > >>> > >>> Andre, care to have a look at this? > >>> > >> > >> I am not sure if the depends-on/default-n/default-y lines are correct. > >> Here, I am on a Intel sandy-bridge CPU, so why do I need to activate > >> any AMD CPU workaround? > > > > > > It is not a workaround, it is about keeping a feature that was in > > powernow-k8 for 2.5 years. AMD CPUs have this sysfs knob for turning on and > > off the boost feature, we want to keep this around for some time for > > compatibility reasons. > > Newer AMD CPUs (Phenoms/Barcelona and up) are now only supported by > > acpi-cpufreq, not by powernow-k8 anymore. > > > > And: it will only be activated on AMD: > > +#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB > > .... > > + * Lets enable it only on AMD CPUs for compatibility reasons and > > + * only if configured. This is considered legacy code, which > > + * will probably be removed at some point in the future. > > + */ > > + if (check_amd_hwpstate_cpu(0)) { > > ... > > > >> > >> [ Linux-Next (next-20120906) ] > >> > >> 19 config X86_ACPI_CPUFREQ > >> 20 tristate "ACPI Processor P-States driver" > >> 21 select CPU_FREQ_TABLE > >> 22 depends on ACPI_PROCESSOR > >> 23 help > >> 24 This driver adds a CPUFreq driver which utilizes the ACPI > >> 25 Processor Performance States. > >> 26 This driver also supports Intel Enhanced Speedstep and newer > >> 27 AMD CPUs. > >> 28 > >> 29 To compile this driver as a module, choose M here: the > >> 30 module will be called acpi-cpufreq. > >> 31 > >> 32 For details, take a look at. > >> 33 > >> 34 If in doubt, say N. > >> 35 > >> 36 config X86_ACPI_CPUFREQ_CPB > >> 37 default y > >> 38 bool "Legacy cpb sysfs knob support for AMD CPUs" > >> 39 depends on X86_ACPI_CPUFREQ&& CPU_SUP_AMD > >> > >> 40 help > >> 41 The powernow-k8 driver used to provide a sysfs knob called > >> "cpb" > >> 42 to disable the Core Performance Boosting feature of AMD CPUs. > >> This > >> 43 file has now been superseeded by the more generic "boost" > >> entry. > >> 44 > >> 45 By enabling this option the acpi_cpufreq driver provides the > >> old > >> 46 entry in addition to the new boost ones, for compatibility > >> reasons. > >> > >> Why is there no depends-on "X86_POWERNOW_K8" (see above help-text)? > > > > > > Because this driver lost the support for newer CPUs and thus also this > > feature. We migrate this feature over to acpi-cpufreq. > > > > > >> I have set CONFIG_CPU_SUP_AMD=y which leads always to > >> CONFIG_X86_ACPI_CPUFREQ_CPB=y. > >> As said Intel SNB CPU! > > > > > > As said it does not hurt if you boot it on an Intel CPU, the code will not > > be run. > > > > > >> > >> What about this (untested)? > >> > >> ----- SNIP ----- > >> config X86_ACPI_CPUFREQ_CPB > >> bool "Legacy cpb sysfs knob support for AMD CPUs" > >> depends on X86_ACPI_CPUFREQ > >> default y if X86_POWERNOW_K8&& CPU_SUP_AMD > > > > > > Powernow-K8 does not support CPB anymore, this code is now in acpi-cpufreq. > > So a dependency on the old driver does not help. > > > > Are there still any problems with this patchset? Or are you only wondering > > about the new config switch? > > > > Just wondering... Fell over it when digging into my boot-problem (this > appeared as a new Kconfig option, so). > Thanks for the explanations! Ah, OK. I got the impression that the patchset caused a problem to happen for you. I suppose it's fine to keep it in linux-next after all, then? Rafael