Re: [PATCH] sky2: Disable MSI on yet another ASUS boards (P6Xxxx)

[David Miller]

From: Takashi Iwai <tiwai@xxxxxxx>
Date: Thu, 29 Aug 2019 07:20:44 +0200

> On Thu, 29 Aug 2019 01:09:37 +0200,
> David Miller wrote:
>> 
>> From: Takashi Iwai <tiwai@xxxxxxx>
>> Date: Wed, 28 Aug 2019 08:31:19 +0200
>> 
>> > A similar workaround for the suspend/resume problem is needed for yet
>> > another ASUS machines, P6X models.  Like the previous fix, the BIOS
>> > doesn't provide the standard DMI_SYS_* entry, so again DMI_BOARD_*
>> > entries are used instead.
>> > 
>> > Reported-and-tested-by: SteveM <swm@xxxxxxxx>
>> > Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
>> 
>> Applied, but this is getting suspicious.
>> 
>> It looks like MSI generally is not restored properly on resume on these
>> boards, so maybe there simply needs to be a generic PCI quirk for that?
> 
> Yes, I wondered that, too.
> But, e.g. HD-audio should use MSI on Intel platforms, and if the
> problem were generic, it must suffer from the same issue, and I
> haven't heard of such, so far.  So it's likely specific to some
> limited devices, as it seems.

There must be some state of MSI state on the sky2 chip that is restored by
most BIOS/chipsets but not this one.

Some part of PCI config space or something.