RE: [PATCH 5/5] thunderbolt: Add support for runtime PM

From: Mario.Limonciello
Date: Mon Jul 09 2018 - 00:20:17 EST


> -----Original Message-----
> From: Yehezkel Bernat [mailto:yehezkelshb@xxxxxxxxx]
> Sent: Sunday, July 8, 2018 2:56 AM
> To: Mika Westerberg
> Cc: lukas@xxxxxxxxx; LKML; Andreas Noever; michael.jamet@xxxxxxxxx;
> rjw@xxxxxxxxxxxxx; christian@xxxxxxxxxx; Limonciello, Mario
> Subject: Re: [PATCH 5/5] thunderbolt: Add support for runtime PM
>
> On Sun, Jul 8, 2018 at 10:31 AM Mika Westerberg
> <mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> >
> > On Sat, Jul 07, 2018 at 11:14:01PM +0200, Lukas Wunner wrote:
> > >
> > > Because I'm fairly certain that
> > > I do not get a PME for the Light Ridge in my MacBook Pro, but I'll test
> > > this once more and modify negotiate_os_control() to grant PME control
> > > to the OS.
> >
> > I think in case of Apple hardware, they handle the in some different
> > means than PME (possibly part of chipset driver or ACPI method/event).
>
> In addition to what already mentioned, many things have changed around power
> management during Alpine Ridge development, some of them came later as FW
> updates (and BIOS changes). Comparing Alpine ridge to Light Ridge here is
> comparing oranges to, well, Apples.

In practice I don't anticipate anyone in the industry outside of Apple wiring up TBT
with RTD3 unless it's at least Alpine Ridge or newer.