Re: Regression on Dell XPS13 (was: [char-misc for 4.10-rc4 V2] mei: bus: enable OS version only for SPT and newer)

Greg KH
2017-01-17T18:33:37Z

On Tue, Jan 17, 2017 at 04:57:49PM +0000, Mario.Limonciello@dell.com wrote:
> So in the <6s scenario, the intel-hid driver is responsible to receive the ACPI
> event and process accordingly. The maintainer has a patch ready for the intel-hid
> portion of this work, but it's currently being reviewed by Intel to ensure it
> can be legally submitted into the kernel.

Who at Intel do I need to go kick to make this mythical legal review
happen faster so we can see the code?

Len and Rafael, what is going on here?

> > 406e79385f3223d82272cf2be86bc95cd000a258 is the first bad commit commit
> > 406e79385f3223d82272cf2be86bc95cd000a258
> > Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > Date: Mon Nov 21 22:45:40 2016 +0100
> >
> > PM / sleep: System sleep state selection interface rework
> >
> > There are systems in which the platform doesn't support any special
> > sleep states, so suspend-to-idle (PM_SUSPEND_FREEZE) is the only
> > available system sleep state. However, some user space frameworks
> > only use the "mem" and (sometimes) "standby" sleep state labels, so
> > the users of those systems need to modify user space in order to be
> > able to use system suspend at all and that may be a pain in practice.
> >
> > Commit 0399d4db3edf (PM / sleep: Introduce command line argument for
> > sleep state enumeration) attempted to address this problem by adding
> > a command line argument to change the meaning of the "mem" string in
> > /sys/power/state to make it trigger suspend-to-idle (instead of
> > suspend-to-RAM).
> >
> > However, there also are systems in which the platform does support
> > special sleep states, but suspend-to-idle is the preferred one anyway
> > (it even may save more energy than the platform-provided sleep states
> > in some cases) and the above commit doesn't help in those cases.
> >
> > For this reason, rework the system sleep state selection interface
> > again (but preserve backwards compatibiliby). Namely, add a new
> > sysfs file, /sys/power/mem_sleep, that will control the system
> > suspend mode triggered by writing "mem" to /sys/power/state (in
> > analogy with what /sys/power/disk does for hibernation). Make it
> > select suspend-to-RAM ("deep" sleep) by default (if supported) and
> > fall back to suspend-to-idle ("s2idle") otherwise and add a new
> > command line argument, mem_sleep_default, allowing that default to
> > be overridden if need be.
> >
> > At the same time, drop the relative_sleep_states command line
> > argument that doesn't make sense any more.
> >
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > Tested-by: Mario Limonciello <mario.limonciello@dell.com>
> >
> > :040000 040000 a5770fe0413cbe7794eab28f72dfe8ede1f090c2
> > a2882c77659517aa7137c930e0e7f178bc76bfbd M Documentation
> > :040000 040000 2594b1a87815173e97199ef9d9c5918fec22fcfd
> > fe0b69953be653644c5366ac631131fdbbdb9bcc M kernel
> > $ git tag --contains 406e79385f3223d82272cf2be86bc95cd000a258
> > v4.10-rc1
> > v4.10-rc2
> > v4.10-rc3
> > ```
> >
> > Please find the config and the bisection log attached. Sometimes I had to
> > cherry-pick build fix commits for PIE enabled GCC on top.
> >
> > Rafael, do you want me to open a bug report for that? Mario, what systems
> > did you actually test this on? (Why isn’t that listed in the commit message?)
> > Mario, do you have access to Dell XPS13 (9360) devices to help getting this
> > fixed?
> >
>
> I tested this on several systems and ensured that the kernel was doing the
> right thing in terms of choosing the correct state to go into.
>
> As I mentioned above, those behaviors are currently expected until these
> types issues are identified and fixed in the proper subsystems. If they
> end up being troublesome to resolve, it's possible to quirk individual systems,
> to disable this behavior and return to traditional S3 but I would prefer to actually
> identify and fix the various problems so that we can push the Linux stack forward.

If the machine stops working on a newer kernel when it used to work
before, then you need to either revert the change, or provide a fix for
it.

I think I might have access to a newer Dell XPS13 now, I'll try to set
it up tomorrow to test 4.10-rc4 out...

thanks,

greg k-h