Re: i8042 AUX port [serio1] suspend takes a second on Dell XPS 13 9360 and TUXEDO Book 1406

From: Paul Menzel
Date: Tue Jan 30 2018 - 13:39:42 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 looking into this. Just to note, that it worked with Linux 4.14.1 from Ubuntu 17.10, so itâs probably something in 4.15. Bisecting will take a bit, as the FTRACE stuff broke in Linux 4.15-rc1 and was only fixed in 4.15-rc9. Hopefully, itâs just one commit I need to backport. Iâll get back to you hopefully at the end of the week.


Kind regards,

Paul

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