On Wed, 12 Jun 2013, Matthew Garrett wrote: > On Tue, Jun 11, 2013 at 02:30:30PM -0700, Larry Baker wrote: > > I have an IBM System x3650 M3 with an Intel Xeon L5630 processor. My > > IBM support team alerted me to an issue with C6 states for those > > processors when running Linux and the intel_idle kernel module is used. > > The IBM solutions page, > > http://www-947.ibm.com/support/entry/portal/docdisplay?lndocid=migr-5091901, > > recommends disabling intel_idle. I propose intel_idle disable C6 for > > the affected processors. > > As you note: > > > > Workaround: It is possible for the BIOS to contain a workaround for > > > this erratum. > > Are you actually seeing this specific problem? If so, you should probably > request a firmware update from IBM. If that's not a possibility, and if it > is necessary to disable package C6 in this situation, it'd be nice to > determine what the BIOS workaround actually does and limit the quirk to > that case. "It is possible for the BIOS to contain a workaround for this erratum." is Intel speak for either "there is a processor microcode update that fixes this", or "there is an undocumented bit somewhere you can toggle that disables some functionality, and also works around this bug". Now, good luck finding out WHICH microcode update is required or which bit to toggle on whichever MSR/PCIe register. It is certainly something we could easily detect and disable C6 only when required (i.e. workaround not in place) or even fix it ourselves... IF we had enough information. -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
