Re: [char-misc for 4.10-rc4 V2] mei: bus: enable OS version only for SPT and newer

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Sun, Jan 15, 2017 at 11:58:30AM +0100, Greg Kroah-Hartman wrote:
> On Sun, Jan 15, 2017 at 07:19:03AM +0000, Winkler, Tomas wrote:
> > > Subject: Re: [char-misc for 4.10-rc4 V2] mei: bus: enable OS version only for SPT
> > > and newer
> > > 
> > > On Sat, Jan 14, 2017 at 08:27:31PM +0100, Paul Menzel wrote:
> > > > Dear Greg,
> > > >
> > > >
> > > > On 2017-01-13 14:00, Greg Kroah-Hartman wrote:
> > > > > On Wed, Jan 11, 2017 at 03:26:06PM +0100, Paul Menzel wrote:
> > > >
> > > > > > On 01/11/17 15:12, Winkler, Tomas wrote:
> > > > > >
> > > > > > > > > On 01/11/17 10:24, Winkler, Tomas wrote:
> > > > > > > > > > >
> > > > > > > > > > > On Wed, Jan 11, 2017 at 01:27:21AM +0200, Tomas Winkler
> > > wrote:
> > > > > > > > > > > > On older platforms the command should be just ignored
> > > > > > > > > > > > by the firmware but some older platforms misbehave so
> > > > > > > > > > > > it's safer to send the command only if required.
> > > > > > > > > > >
> > > > > > > > > > > Thanks! This fixes suspend-to-ram for me (on a Thinkpad x201s).
> > > > > > > > > >
> > > > > > > > > > What about Dell XPS13?
> > > > > > > > >
> > > > > > > > > With Linus' master branch from today, and Greg's
> > > > > > > > > char-misc-linus merged
> > > > > > > > > (Merge: 807b93e995d1 546cf3ef9c92), the regression is still there.
> > > > > > > >
> > > > > > > > Hmm, this should work on KBL....
> > > > > > > >
> > > > > > > > > I am now building a Linux kernel image with the two commits
> > > > > > > > > touching
> > > > > > > > > `bus- fixup.c` reverted.
> > > > > > > >
> > > > > > > > Thanks for the effort.
> > > > > > > >
> > > > > > > > > Do you want me to open a separate bug report for that, or
> > > > > > > > > continue debugging in the existing report [1], which is currently
> > > marked as resolved?
> > > > > > > >
> > > > > > > > Let's get some more data, shouldn't take long time.
> > > > > > > > >
> > > > > > > > > Do you have Kaby Lake devices sitting around for testing?
> > > > > > > >
> > > > > > > > We will of course try to reproduce the issue locally.
> > > > > > >
> > > > > > > Paul, currently we cannot reproduce this issue on Kaby Lake
> > > > > > > platforms on our side,
> > > > > >
> > > > > > It looks like it’s a different issue. Reverting the two commits
> > > > > > touching `bus-fixup.c`, did not help.
> > > > > >
> > > > > > > we would be great for more debug data from your side.
> > > > > > > You can get more info by enabling  mode debug logs
> > > > > > >
> > > > > > > echo -n 'module mei +lfp' >
> > > > > > > /sys/kernel/debug/dynamic_debug/control
> > > > > > > echo -n 'module mei_me +lfp' >
> > > > > > > /sys/kernel/debug/dynamic_debug/control
> > > > > >
> > > > > > I am currently bisecting to find the culprit. 13 steps will take
> > > > > > some time though.
> > > > >
> > > > > I can duplicate this on my laptop here as well :(
> > > >
> > > > Which system do you have?
> > > 
> > > A Dell XPS13, don't know what cpu type it is, here's the output of one cpu from
> > > /proc/cpuinfo
> > > 
> > > processor	: 3
> > > vendor_id	: GenuineIntel
> > > cpu family	: 6
> > > model		: 78
> > > model name	: Intel(R) Core(TM) i7-6560U CPU @ 2.20GHz
> > > stepping	: 3
> > > microcode	: 0x8a
> > > cpu MHz		: 712.207
> > > cache size	: 4096 KB
> > > physical id	: 0
> > > siblings	: 4
> > > core id		: 1
> > > cpu cores	: 2
> > > apicid		: 3
> > > initial apicid	: 3
> > > fpu		: yes
> > > fpu_exception	: yes
> > > cpuid level	: 22
> > > wp		: yes
> > > flags		: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
> > > cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx
> > > pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts rep_good nopl
> > > xtopology nonstop_tsc aperfmperf eagerfpu pni pclmulqdq dtes64 monitor
> > > ds_cpl vmx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic
> > > movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm
> > > 3dnowprefetch epb intel_pt tpr_shadow vnmi flexpriority ept vpid fsgsbase
> > > tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx rdseed adx smap clflushopt
> > > xsaveopt xsavec xgetbv1 xsaves dtherm ida arat pln pts hwp hwp_notify
> > > hwp_act_window hwp_epp
> > > bugs		:
> > > bogomips	: 4419.34
> > > clflush size	: 64
> > > cache_alignment	: 64
> > > address sizes	: 39 bits physical, 48 bits virtual
> > > power management:
> > > 
> > > > > Did you get anywhere with your bisection?
> > > >
> > > > Sorry, I replied to a different message with my status.
> > > >
> > > > Please see my status below. I’ll have access to the machine on Monday
> > > again.
> > > >
> > > > ```
> > > > $ git bisect log
> > > > git bisect start
> > > > # good: [69973b830859bc6529a7a0468ba0d80ee5117826] Linux 4.9 git
> > > > bisect good 69973b830859bc6529a7a0468ba0d80ee5117826
> > > > # good: [69973b830859bc6529a7a0468ba0d80ee5117826] Linux 4.9 git
> > > > bisect good 69973b830859bc6529a7a0468ba0d80ee5117826
> > > > # bad: [a121103c922847ba5010819a3f250f1f7fc84ab8] Linux 4.10-⁠rc3 git
> > > > bisect bad a121103c922847ba5010819a3f250f1f7fc84ab8
> > > > # bad: [72cca7baf4fba777b8ab770b902cf2e08941773f] Merge tag
> > > > 'staging-4.10-rc1' of
> > > > git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
> > > > git bisect bad 72cca7baf4fba777b8ab770b902cf2e08941773f
> > > > # good: [b8d2798f32785398fcd1c48ea80c0c6c5ab88537] Merge tag 'clk-for-
> > > linus'
> > > > of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
> > > > git bisect good b8d2798f32785398fcd1c48ea80c0c6c5ab88537
> > > > # good: [9439b3710df688d853eb6cb4851256f2c92b1797] Merge tag 'drm-
> > > for-v4.10'
> > > > of git://people.freedesktop.org/~airlied/linux
> > > > git bisect good 9439b3710df688d853eb6cb4851256f2c92b1797
> > > > ```
> > > >
> > > 
> > > You are close!  I'll try bisection tomorrow if I have some spare time.
> > > 
> > > thanks,
> > 
> > Greg,  is that same Laptop mode as Paul's, you've experience the issue on?
> 
> It's the same model name, but as this model has been shipped with many
> different CPU versions over the years, I'm not sure if it is the exact
> same one.

Ok, 4.10-rc4 seems to have fixed this issue with me.  I don't know what
it was, but I can't duplicate it anymore.

Paul, are you still having this issue?

thanks,

greg k-h