linux-kernel - Re: [PATCH] ACPI / LPSS: Don't skip late system PM ops for hibernate on BYT/CHT

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Message-ID: <beab21cb-9f89-b934-e0a4-2fd85c69f4e6@uwyo.edu>
Date:   Thu, 25 Apr 2019 16:38:34 +0000
From:   "Robert R. Howell" <RHowell@...o.edu>
To:     "Rafael J. Wysocki" <rafael@...nel.org>
CC:     Hans de Goede <hdegoede@...hat.com>,
        Kai-Heng Feng <kai.heng.feng@...onical.com>,
        "rjw@...ysocki.net" <rjw@...ysocki.net>,
        "lenb@...nel.org" <lenb@...nel.org>,
        "linux-acpi@...r.kernel.org" <linux-acpi@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "Robert R. Howell" <RHowell@...o.edu>
Subject: Re: [PATCH] ACPI / LPSS: Don't skip late system PM ops for hibernate
 on BYT/CHT

On 4/24/19 1:20 AM, Rafael J. Wysocki wrote:

> On Tue, Apr 23, 2019 at 10:03 PM Robert R. Howell <RHowell@...o.edu> wrote:
>>
>> On 4/23/19 2:07 AM, Rafael J. Wysocki wrote:
>>>
>>> On Sat, Apr 20, 2019 at 12:44 AM Robert R. Howell <RHowell@...o.edu> wrote:
>>>>
>>>> On 4/18/19 5:42 AM, Hans de Goede wrote:
>>>>
>>>>>> On 4/8/19 2:16 AM, Hans de Goede wrote:>
>>>>>>>
>>>>>>> Hmm, interesting so you have hibernation working on a T100TA
>>>>>>> (with 5.0 + 02e45646d53b reverted), right ?
>>>>>>>
>>>>
>>>>
>>>> I've managed to find a way around the i2c_designware timeout issues
>>>> on the T100TA's.  The key is to NOT set DPM_FLAG_SMART_SUSPEND,
>>>> which was added in the 02e45646d53b commit.
>>>>
>>>> To test that I've started with a 5.1-rc5 kernel, applied your recent patch
>>>> to acpi_lpss.c, then apply the following patch of mine, removing
>>>> DPM_FLAG_SMART_SUSPEND.  (For the T100 hardware I need to apply some
>>>> other patches as well but those are not related to the i2c-designware or
>>>> acpi issues addressed here.)
>>>>
>>>> On a resume from hibernation I still see one error:
>>>>   "i2c_designware 80860F41:00: Error i2c_dw_xfer called while suspended"
>>>> but I no longer get the i2c_designware timeouts, and audio does now work
>>>> after the resume.
>>>>
>>>> Removing DPM_FLAG_SMART_SUSPEND may not be what you want for other
>>>> hardware, but perhaps this will give you a clue as to what is going
>>>> wrong with hibernate/resume on the T100TA's.
>>>
>>> What if you drop DPM_FLAG_LEAVE_SUSPENDED alone instead?
>>>
>>
>> I did try dropping just DPM_FLAG_LEAVE_SUSPENDED, dropping just
>> DPM_FLAG_SMART_SUSPEND, and dropping both flags.  When I just drop
>> DPM_FLAG_LEAVE_SUSPENDED I still get the i2c_designware timeouts
>> after the resume.  If I drop just DPM_FLAG_SMART_SUSPEND or drop both,
>> then the timeouts go away.
> 
> OK, thanks!
> 
> Is non-hibernation system suspend affected too?

I just ran some tests on a T100TA, using the 5.1-rc5 code with Hans' patch applied 
but without any changes to i2c-designware-platdrv.c, so the 
DPM_FLAG_SMART_PREPARE, DPM_FLAG_SMART_SUSPEND, and DPM_FLAG_LEAVE_SUSPENDED flags 
are all set.  

Suspend does work OK, and after resume I do NOT get any of the crippling 
i2c_designware timeout errors which cause sound to fail after hibernate.  I DO see one 
  "i2c_designware 80860F41:00: Error i2c_dw_xfer call while suspended"
error on resume, just as I do on hibernate.  I've attached a portion of dmesg below.
The "asus_wmi:  Unknown key 79 pressed" error is a glitch which occurs 
intermittently on these machines, but doesn't seem related to the other issues.  
I had one test run when it was absent but the rest of the messages were the 
same -- but then kept getting that unknown key error on all my later tries.

I did notice the "2sidle" in the following rather than "shallow" or "deep".  A
cat of /sys/power/state shows "freeze mem disk" but a
cat of /sys/power/mem_sleep" shows only "[s2idle] so it looks like shallow and deep 
are not enabled for this system.  I did check the input power (or really current) 
as it went into suspend and the micro-usb power input drops from about 
0.5 amps to 0.05 amps.  But clearly a lot of devices are still active, as movement 
of a bluetooth mouse (the MX Anywhere 2) will wake it from suspend.  That presumably is 
why suspend doesn't trigger the same i2c_designware problems as hibernate.

Let me know if I can do any other tests.

Bob Howell

----DMESG OUTPUT ON SUSPEND------------------
[   71.791495] NET: Registered protocol family 38
[   73.150736] input: MX Anywhere 2 Keyboard as /devices/virtual/misc/uhid/0005:046D:B013.0005/input/input24
[   73.156612] input: MX Anywhere 2 Mouse as /devices/virtual/misc/uhid/0005:046D:B013.0005/input/input25
[   73.159504] hid-generic 0005:046D:B013.0005: input,hidraw4: BLUETOOTH HID v0.07 Keyboard [MX Anywhere 2] on 74:D0:2B:DF:77:E9
[  102.719170] asus_wmi: Unknown key 79 pressed
[  102.897214] asus_wmi: Unknown key 79 pressed
[  104.298409] PM: suspend entry (s2idle)
[  104.298414] PM: Syncing filesystems ... done.
[  105.410883] Freezing user space processes ... (elapsed 0.002 seconds) done.
[  105.413556] OOM killer disabled.
[  105.413558] Freezing remaining freezable tasks ... (elapsed 0.001 seconds) done.
[  123.353720] i2c_designware 80860F41:00: Error i2c_dw_xfer call while suspended
[  123.635028] ACPI: button: The lid device is not compliant to SW_LID.
[  124.086421] OOM killer enabled.
[  124.086491] Restarting tasks ... done.
[  124.120647] PM: suspend exit
[  124.939566] asus_wmi: Unknown key 79 pressed