[PATCH] UBUNTU: SAUCE: PCI/ASPM: Add AlderLake ASPM support for links under VMD domain

[Bao, Ping A]

Hi Kai-Heng,

> -----Original Message-----
> From: Kai-Heng Feng <kai.heng.feng at canonical.com>
> Sent: Tuesday, July 27, 2021 7:44 PM
> To: pingbao at gmail.com
> Cc: Kernel team list <kernel-team at lists.ubuntu.com>; Bao, Ping A
> <ping.a.bao at intel.com>; Wong, Anthony <anthony.wong at canonical.com>;
> David E. Box <david.e.box at linux.intel.com>
> Subject: Re: [PATCH] UBUNTU: SAUCE: PCI/ASPM: Add AlderLake ASPM support
> for links under VMD domain
> 
> [+Cc Anthony, David]
> 
> Hi Ping,
> 
> On Fri, Jul 23, 2021 at 1:41 PM Ping Bao <pingbao at gmail.com> wrote:
> >
> > BugLink: https://bugs.launchpad.net/bugs/1889384
> >
> > Add AlderLake ASPM support for links under VMD to reach deeper power
> > saving state.
> 
> I was told by David that ADL VMD ASPM should be enabled by BIOS. So wonder
> why the patch is necessary?

Just talked with David. This feature has not been implemented yet.

Ping

> 
> Kai-Heng
> 
> >
> > Signed-off-by: Ping Bao <ping.a.bao at intel.com>
> > ---
> >  drivers/pci/quirks.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index
> > fb13b3109a43..baa727330cdc 100644
> > --- a/drivers/pci/quirks.c
> > +++ b/drivers/pci/quirks.c
> > @@ -5650,7 +5650,7 @@ DECLARE_PCI_FIXUP_CLASS_HEADER(0x1ac1,
> 0x089a,
> >                                PCI_CLASS_NOT_DEFINED, 8,
> > apex_pci_fixup_class);
> >
> >  /*
> > - * Device [8086:9a09], [8086:a0b0] and [8086:a0bc]
> > + * Device [8086:9a09], [8086:a0b0], [8086:a0bc] and [8086:464d]
> >   * BIOS may not be able to access config space of devices under VMD domain,
> so
> >   * it relies on software to enable ASPM for links under VMD.
> >   */
> > @@ -5658,6 +5658,7 @@ static const struct pci_device_id vmd_bridge_tbl[] =
> {
> >         { PCI_VDEVICE(INTEL, 0x9a09) },
> >         { PCI_VDEVICE(INTEL, 0xa0b0) },
> >         { PCI_VDEVICE(INTEL, 0xa0bc) },
> > +       { PCI_VDEVICE(INTEL, 0x464d) },
> >         { }
> >  };
> >
> > --
> > 2.25.1
> >
> >
> > --
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> > kernel-team at lists.ubuntu.com
> > https://lists.ubuntu.com/mailman/listinfo/kernel-team