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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Wed, 26 Aug 2020 15:20:12 +0200
Message-ID: <CAJZ5v0iBn8M062CpMfv8sJ9tavMjrfrDtN6aTFq7DGV60X5iLQ@mail.gmail.com>
Subject: Re: [PATCH] intel_idle: Add ICL support
To:     Artem Bityutskiy <dedekind1@gmail.com>
Cc:     Guilhem Lettron <guilhem@barpilot.io>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Jacob Pan <jacob.jun.pan@linux.intel.com>,
        Len Brown <lenb@kernel.org>,
        Linux PM <linux-pm@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Wed, Aug 26, 2020 at 3:09 PM Artem Bityutskiy <dedekind1@gmail.com> wrote:
>
> On Wed, 2020-08-26 at 15:03 +0200, Guilhem Lettron wrote:
> > On Wed, 26 Aug 2020 at 14:43, Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > On Wed, Aug 26, 2020 at 2:05 PM Guilhem Lettron <guilhem@barpilot.io> wrote:
> > > > Use the same C-states as SKL
> > >
> > > Why is this change needed?
> >
> > On my laptop, a Dell XPS 13 7390 2-in-1 with i7-1065G7, ACPI only
> > report "C1_ACPI", "C2_ACPI" and "C3_ACPI".
>
> Did you try to dig into the BIOS menus and check if you can enable
> more/deeper C-states?

I would be surprised if there were settings for that in the BIOS, as
Windows only expects #1, C2 and C3 AFAICS.

It might be possible to disable C1E autopromotion, but that option is
not likely to be available on a laptop.

Cheers!