From: Tom Cook <tom.k.cook@gmail.com>
To: linux-kernel@vger.kernel.org
Subject: Re: Power management - HP 15-ds0502na
Date: Mon, 4 Nov 2019 14:32:30 +0000 [thread overview]
Message-ID: <CAFSh4UxquUDSbw+JA1t=VBpe1yn+ar3MjsFbJP9bRo5a3BWAnw@mail.gmail.com> (raw)
In-Reply-To: <20191104135111.GF28764@mit.edu>
On Mon, Nov 4, 2019 at 1:51 PM Theodore Y. Ts'o <tytso@mit.edu> wrote:
> This is actually the laptop's ACPI and/or EC not supporting
> suspend-to-ram at all. Suspend to idle is the new hotness, because it
> gives the OS much more control (but also gives the OS much more
> opportunity to screw up). The Dell XPS 13 (models 9370 and 9380)
> supports both s2idle and s2ram, but s2idle doesn't work well at all on
> Linux. (Well, at least not the upstream kernels; the official Dell
> Ubuntu kernel and userspace apparently has enough tweaks that it works
> well.)
s2idle sort of works - the thing appears to go to sleep and wake up
okay - but the power savings are not really enough to make it
worthwhile. Putting it into s2idle state and putting it in a bag
results in a very hot laptop - and of course that makes battery life
not great. I'm guessing this is the Ryzen 7 CPU idle states not being
very well supported?
> > * There are a few devices that appear to be on I2C buses and declared
> > in the ACPI tables (eg the fingerprint sensor) which don't show up
> > under Linux. They did under Windows, until I blew the Windows
> > installation away to install Linux, and I'm assuming that Windows
> > found them through the ACPI DSDT. Now thinking it may have been handy
> > to keep Windows around for debugging, but that's regrets for you.
>
> Even if they showed up, it's unclear the device driver would exist for
> Linux. Most fingerprint readers have proprietary interfaces and
> aren't well supported by Linux in general.
Yes, understood. But the first step would be enumerating them through
the ACPI tables (if indeed that is how they are announced).
> > Is this the right place to raise this? If there's some other place
> > that Linux ACPI issues are dealt with, please point me there as I've
> > not had any luck googling.
>
> There is the linux-acpi@vger.kernel.org mailing list and the
> linux-pm@vger.kernel.org (pm --> "power management") where you might
> try asking about the s2idle. A lot of the issues with s2idle appear
> to be very device driver specific, and not about the power management
> core, so it's unclear folks on those lists will be able to help. But
> it's worth a try...
Thanks.
Tom
next prev parent reply other threads:[~2019-11-04 14:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-04 11:21 Power management - HP 15-ds0502na Tom Cook
2019-11-04 13:51 ` Theodore Y. Ts'o
2019-11-04 14:32 ` Tom Cook [this message]
2019-11-04 15:06 ` Theodore Y. Ts'o
2019-11-04 15:45 ` Theodore Y. Ts'o
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