Re: i8042 AUX port [serio1] suspend takes a second on Dell XPS 13 9360

From: Paul Menzel
Date: Wed Feb 14 2018 - 11:41:38 EST


Dear Dmitry,


On 01/30/18 19:07, Dmitry Torokhov wrote:
On Tue, Jan 30, 2018 at 09:52:45AM -0800, Dmitry Torokhov wrote:

On Tue, Jan 30, 2018 at 06:36:34PM +0100, Paul Menzel wrote:

I do not know, when it started, but with Linux 4.14-rc8 and 4.15,
benchmarking suspend and resume time with `sleepgraph.py` [1][2], there is a
regression, that i8042 AUX port [serio1] suspend takes a second on Dell XPS
13 9360 and TUXEDO Book 1406.

It would be really helpful to know when the regression started.

So the reason it takes longer is because the touchpad does not want to
talk to us for some reason and we wait until commands time out:

[ 94.591636] calling serio1+ @ 2299, parent: i8042
[ 94.794292] psmouse serio1: Failed to disable mouse on isa0060/serio1
[ 95.593303] call serio1+ returned 0 after 974280 usecs

but it is not clear why it happens, I do not think we changed anything
in that path for a while, so it might be some other change affecting
things indirectly. I'm afraid you'll have to narrow the scope, and
ideally bisect.

Thank you for your replies. First of all, it looks like *only* the Dell system is effected as I was unable to reproduce it on the TUXEDO Book 1406. I have to verify that by finding old log files.

Starting the bisect between 4.14 and 4.15-rc1 it turns out, that the problem is also reproducible with 4.14, and I remembered wrong. Looking more into it, I could also reproduce it with Linux 4.13.0-32-generic from Ubuntu 16.04 (Hardware Enablement Stack). But my old logs do not show the problem. As the UEFI firmware was updated to version 2.5.0 in the meantime, it could also be related to that.

So it turns out, with 4.16-rc1 I see this delay/failure message only during the first suspend. Suspending a second time, I do not see the message.

Any hints how to debug this further are much appreciated. Could it be related to the embedded controller?


Kind regards,

Paul

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