Hi Jerome,

-----Original Message-----
From: Jérôme de Bretagne [mailto:jerome.debretagne@gmail.com]
Sent: Wednesday, June 7, 2017 6:06 PM
To: ACPI Devel Maling List <redacted>; linux-
pm@vger.kernel.org; Rafael J. Wysocki [off-list ref]
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>; Darren Hart
[off-list ref]; Srinivas Pandruvada
[off-list ref]; Mika Westerberg
[off-list ref]; Limonciello, Mario
[off-list ref]
Subject: Re: [PATCH 0/3] ACPI / sleep: Support power button wakeup from S2I on
recent Dell laptops

Hi,

Here is some feedback for Dell Latitude 7275, as suggested by Srinivas
in https://bugzilla.kernel.org/show_bug.cgi?id=195897#c15 .

For some context on that model, suspend-to-RAM is not safe as the
system hangs (raised in the above bug report). I'm wondering if this
is expected somehow, due to S3 not being supported on that model, as
discussed for the XPS 13 9365. Maybe Mario or someone else from Dell
would be able to confirm this point.

The Latitude 7275 was not a machine that was tested with Linux during 
development.
This machine shipped with Windows 8, right?
I believe this machine also supports Connected Standby (the precursor
to Modern Standby that behaves very similarly).

I have an ask out to someone who can confirm that.	

While it's not set by default, suspend-to-idle works fine. However the
power button needs a very long press of about 6-7s to trigger the
wake-up (quite surprising at first).

I've applied Rafael's patch series on 4.12-rc4, with the 3rd patch
modified to add the Latitude 7275 DMI values, to check if the proposed
fix for the XPS 13 9360 and 9365 could also work for this other quite
recent Dell model.

Sadly with the latest BIOS 1.1.31, this patch set doesn't seem to
change anything: the long press is still needed.

Surprisingly and more for reference I suppose, this patch set works as
intended with an older BIOS 1.1.20 : the system can then be woken up
from system-to-idle with a usual short press. Cf.
https://bugzilla.kernel.org/show_bug.cgi?id=195897#c9 for more details
about why I've downgraded to and tested that specific older BIOS.

I'm wondering if there could be ways to modify slightly this patch
series to also cover the Latitude 7275 when running the current BIOS.
If I can provide any inputs that could be useful to investigate,
please let me know.

Thanks,
Jérome