Messages in this thread | | | From | Chris Chiu <> | Date | Thu, 16 Aug 2018 16:18:54 +0800 | Subject | Re: Keyboard lost after exit s2idle on ASUS UX433FN |
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On Thu, Aug 16, 2018 at 3:26 PM, Rafael J. Wysocki <rafael@kernel.org> wrote: > On Thu, Aug 16, 2018 at 4:45 AM Chris Chiu <chiu@endlessm.com> wrote: >> >> Hi, >> We recently hit a weird problem on the ASUS laptop UX433FN with >> latest Intel Core i7-8565U CPU on kernel 4.18. The keyboard stops >> functioning after exit s2idle. It stops firing interrupts after resume >> on any keypress. We thought it should be something wrong with i8042 >> driver or even atkbd driver, so we tried to skip the suspend/resume >> path of i8042 and input devices but no luck. >> >> Then we tried to hack the s2idle code to fail right before it goes >> into the idle state to find out which code really cause the keyboard >> broken. It comes with an interesting finding that if it aborts s2idle >> before cpuidle_resume() in s2idle_enter(), the keyboard is fine. If it >> aborts after cpuidle_resume, then the keyboard down. At least it >> proves that even with dpm_noirq_begin() and >> dpm_noirq_suspend_devices() executed, the keyboard is still alive. >> There should be something wrong with the cpuidle. >> >> Going deeper into intel_idle_s2idle() which is invoked by >> cpuidle_enter_s2idle(), we found that the keyboard interrupt will no >> longer function after mwait_idle_with_hints() which just simply >> executing intel monitor and mwait instructions. So I don't know what >> should be the next step I can take. Can anyone give some pieces of >> advice? > > It may indicate that the deepest C-states used by s2idle simply don't > work correctly on the affected system. > > To verify this, you can try to disable the deepest C-states via sysfs > using the "disable" attribute under > /sys/devices/system/cpu/cpuX/cpuidle/stateX/ > Thanks for the great help. I can have the keyboard work after s2idle with the following command
echo 1 > /sys/devices/system/cpu/cpuX/cpuidle/state8/disable
cpuX, X can be 0 to 7 on this CPU. And only state8 disable would work, it fails on state 0~7 disabled.
There're 9 (0-8) states on the cpuidle of this machine. However, I have another laptop with the same CPU Intel Core i7-8565U which only have 4(0-3) states under the same '/sys/devices/system/cpu/cpuX/cpuidle/' entry. Sorry that I don't have enough background knowledge about cpuidle. I thought the #C state should be depend on CPU, but why the same i7-8565 has different number of C-states? And for this case, should I just disable C-8 state or there should be a generic fix with it?
> Is s2idle the default suspend method on that system? If so, have you > checked whether or not suspend-to-RAM works too? >
Yes, it's default s2idle. If I do 'echo mem > /sys/power/state', the keyboard would still fail.
> Thanks, > Rafael
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