Messages in this thread | | | Date | Wed, 28 Aug 2019 07:13:23 -0400 | From | Sasha Levin <> | Subject | Re: Patch "x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume" has been added to the 4.4-stable tree |
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On Wed, Aug 28, 2019 at 11:11:55AM +0200, Greg KH wrote: >On Wed, Aug 28, 2019 at 05:00:44PM +0800, Yu Chen wrote: >> On Wed, Aug 28, 2019 at 10:43:51AM +0200, Greg KH wrote: >> > On Wed, Aug 28, 2019 at 12:12:39AM -0400, Sasha Levin wrote: >> > > This is a note to let you know that I've just added the patch titled >> > > >> > > x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume >> > > >> > > to the 4.4-stable tree which can be found at: >> > > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary >> > > >> > > The filename of the patch is: >> > > x86-pm-introduce-quirk-framework-to-save-restore-ext.patch >> > > and it can be found in the queue-4.4 subdirectory. >> > > >> > > If you, or anyone else, feels it should not be added to the stable tree, >> > > please let <stable@vger.kernel.org> know about it. >> > > >> > > >> > > >> > > commit d63273440aa0fdebc30d0c931f15f79beb213134 >> > > Author: Chen Yu <yu.c.chen@intel.com> >> > > Date: Wed Nov 25 01:03:41 2015 +0800 >> > > >> > > x86/pm: Introduce quirk framework to save/restore extra MSR registers around suspend/resume >> > > >> > > A bug was reported that on certain Broadwell platforms, after >> > > resuming from S3, the CPU is running at an anomalously low >> > > speed. >> > > >> > > It turns out that the BIOS has modified the value of the >> > > THERM_CONTROL register during S3, and changed it from 0 to 0x10, >> > > thus enabled clock modulation(bit4), but with undefined CPU Duty >> > > Cycle(bit1:3) - which causes the problem. >> > > >> > > Here is a simple scenario to reproduce the issue: >> > > >> > > 1. Boot up the system >> > > 2. Get MSR 0x19a, it should be 0 >> > > 3. Put the system into sleep, then wake it up >> > > 4. Get MSR 0x19a, it shows 0x10, while it should be 0 >> > > >> > > Although some BIOSen want to change the CPU Duty Cycle during >> > > S3, in our case we don't want the BIOS to do any modification. >> > > >> > > Fix this issue by introducing a more generic x86 framework to >> > > save/restore specified MSR registers(THERM_CONTROL in this case) >> > > for suspend/resume. This allows us to fix similar bugs in a much >> > > simpler way in the future. >> > > >> > > When the kernel wants to protect certain MSRs during suspending, >> > > we simply add a quirk entry in msr_save_dmi_table, and customize >> > > the MSR registers inside the quirk callback, for example: >> > > >> > > u32 msr_id_need_to_save[] = {MSR_ID0, MSR_ID1, MSR_ID2...}; >> > > >> > > and the quirk mechanism ensures that, once resumed from suspend, >> > > the MSRs indicated by these IDs will be restored to their >> > > original, pre-suspend values. >> > > >> > > Since both 64-bit and 32-bit kernels are affected, this patch >> > > covers the common 64/32-bit suspend/resume code path. And >> > > because the MSRs specified by the user might not be available or >> > > readable in any situation, we use rdmsrl_safe() to safely save >> > > these MSRs. >> > > >> > > Reported-and-tested-by: Marcin Kaszewski <marcin.kaszewski@intel.com> >> > > Signed-off-by: Chen Yu <yu.c.chen@intel.com> >> > > Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> >> > > Acked-by: Pavel Machek <pavel@ucw.cz> >> > > Cc: Andy Lutomirski <luto@amacapital.net> >> > > Cc: Borislav Petkov <bp@alien8.de> >> > > Cc: Brian Gerst <brgerst@gmail.com> >> > > Cc: Denys Vlasenko <dvlasenk@redhat.com> >> > > Cc: H. Peter Anvin <hpa@zytor.com> >> > > Cc: Linus Torvalds <torvalds@linux-foundation.org> >> > > Cc: Peter Zijlstra <peterz@infradead.org> >> > > Cc: Thomas Gleixner <tglx@linutronix.de> >> > > Cc: bp@suse.de >> > > Cc: len.brown@intel.com >> > > Cc: linux@horizon.com >> > > Cc: luto@kernel.org >> > > Cc: rjw@rjwysocki.net >> > > Link: http://lkml.kernel.org/r/c9abdcbc173dd2f57e8990e304376f19287e92ba.1448382971.git.yu.c.chen@intel.com >> > > [ More edits to the naming of data structures. ] >> > > Signed-off-by: Ingo Molnar <mingo@kernel.org> >> > >> > No git id of the patch in Linus's tree, or your signed-off-by? >> > >> I think the commit id in Linus'tree should be 7a9c2dd08eadd5c6943115dbbec040c38d2e0822 > >Ah, and Sasha added it because a later patch needed it :( > >Sasha, can you fix this patch's headers up to be in the "proper" format?
Yes, I brought it in as a dependency but cherry picked instead of using my scripts by mistake. I'll fix up the patch in the queue.
-- Thanks, Sasha
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