RE: [PATCH 3/3] soundwire: dmi-quirks: Disable ghost Realtek devices

[Liao, Bard]

> -----Original Message-----
> From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxx>
> Sent: Thursday, May 21, 2026 1:17 AM
> To: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx>; broonie@xxxxxxxxxx;
> vkoul@xxxxxxxxxx
> Cc: lgirdwood@xxxxxxxxx; yung-chuan.liao@xxxxxxxxxxxxxxx;
> peter.ujfalusi@xxxxxxxxxxxxxxx; oder_chiou@xxxxxxxxxxx;
> jack.yu@xxxxxxxxxxx; shumingf@xxxxxxxxxxx; linux-sound@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; patches@xxxxxxxxxxxxxxxxxxxxx
> Subject: Re: [PATCH 3/3] soundwire: dmi-quirks: Disable ghost Realtek devices
> 
> On 5/20/26 18:36, Charles Keepax wrote:
> > Many systems ship with a Realtek audio codec in the ACPI that doesn't
> > physically exist in the system. This confuses the newer function
> > topology system that creates the soundcard, as it builds the card based
> > on the ACPI information.
> >
> > Whilst we are working with the laptop vendors to try and stop this
> > happening there are quite a few systems where this has shipped. Add a
> > quirk to disable this "ghost" device.
> >
> > Currently this patch should cover:
> >  - Asus UX5406AA
> >  - Lenovo Yoga Pro 9i (83SF)
> >  - Lenovo Yoga Slim 7 Ultra (83QK)
> 
> if this broken ACPI stuff works for Windows then it'll be an uphill battle...

We already informed the OEMs. Hope they can fix in the next generation
products.

> 
> Could we filter instead those 'ghost' devices if they fail to appear in the new
> ACPI table that describes all the endpoints and card topology?

Sorry Pierre, I am not sure if I get your question correctly.
The 'ghost' device has a complete DisCo properties description in the
ACPI table. We could check if the device is ever attached. But
we need to set a timeout time and wait until timeout to claim
the device is not present. It seems not be realistic to wait say 3
seconds in each boot.