+People in community.
Rodrigo,
Thanks for the kind info.
What's the answer to below question?
I find i915 binds one pipeline per display. It means even with DP1.2 MST, i915
driver still restricts the display number to the display pipeline
number. Am I right?
In addition, I might mislead you at case 1). The NUC has 1 HDMI interface and
1 USB type-C interface. I connect a display by HDMI to that HDMI interface.
Then, I connect other 2 displays by the CE-LINK box which connect to the usb
type-C interface.
Yanmin
> -Original Message-
> From: Vivi, Rodrigo
> Sent: Tuesday, December 04, 2018 6:28 AM
> To: Zhang, Yanmin
> Cc: Syrjala, Ville
> Subject: Re: DP1.2 MST HUB
>
> Hi there,
>
> again, please ask these questions in public mailing lists.
>
> On Sun, Dec 02, 2018 at 06:43:31PM -0800, Zhang, Yanmin wrote:
> > Here is the result.
> >
> > 1) If I use a CE-LINK 1-to-2 converter, 1usb type-C in, and 2 HDMI out, it
> > works
> with my NUC. This NUC has 1 HDMI and 1 USB type C interfaces.
> > a) If I connect 1 display by HDMI, and other 2 displays by the CE-LINK,
> android refuses (logcat shows No permission) to show application GUI to the
> 3rd
> display. It might be an issue of Android.
> > b) If I remove HDMI display, but just connect other 2 displays by
> > CE-LINK,
> both displays can work.
> >
> > 2) If I use CLUB-3D box which has 1 DP in and 4 DP out, I have to use a usb
> > type-
> C to DP cable, then connect to a DP converter with 2 daughter interfaces, then
> connect to the CLUB-3D, then to 2 displays. Kernel driver reports the
> displays, but
> the display is always black. Perhaps there are too many converters on the
> connection path.
> > If I use CLUB-3D box to connect to my desktop which uses NEVIDE display
> > card,
> it works well.
> >
> >
> > At 1).b) case, I find i915 binds one pipeline per display. It means even
> > with
> DP1.2 MST, i915 driver still restricts the display number to the display
> pipeline
> number. Am I right? Can we extend display number more than pipeline number?
>
> I'm not sure if I followed your case here, but 2 things here:
>
> 1. it seems that
> you might be reached the maximun number of allocated vcpi here.
>
> Just by leaving cable connected the vpci gets reserved on drm if I remember
> correctly so things might not fully work.
>
> But it is hard to tell without any log. if that is the case.
>
> 2. About the "extend display part" there is currently a limitation of the
> vertical
> size that Ville was working to solve that.
> I'm not sure about the status.
>
> Thanks,
> Rodrigo.
>
> >
> > Thanks,
> > Yanmin
> >
> > > -Original Message-
> > > From: Zhang, Yanmin
> > > Sent: Friday, November 30, 2018 8:24 AM
> > > To: Vivi, Rodrigo
> > > Cc: Syrjala, Ville
> > > Subject: RE: DP1.2 MST HUB
> > >
> > > Rodrigo,
> > >
> > > Thanks for the kind info. 'enabling' here is to check if DP1.2 MST
> > > (perhaps with
> > > HBR2) can work with intel NUC (with type-C DP). Later on, check it
> > > on new IVE system which might be based on ElkhartLake or Tigerlake.
> > > If it doesn't work, I have to check if it's about either MST HUB
> > > hardware, or software such like i915 driver. Basically, I am not
> > > i915 driver expert, but I assume you guys already enabled it well.
> > >
> > > I already ordered a MST HUB https://www.club-
> > > 3d.com/en/detail/2411/multi_stream_transport_(mst)_hub_displayportt_
> > > 1.2_qu ad_monitor/, and another one which has an input of USB Type-C
> > > and 2 HDMI outputs.
> > > Hope it can work.
> > >
> > > Even when it works, IVE system might not use the MST HUB directly. I
> > > suppose IVE hardware architect will use specific AIC to implement
> > > MST HUB capability on board. Currently, I want to prove DP 1.2 MST can
> > > work
> well on Intel chips.
> > >
> > > I will keep you guys posted.
> > >
> > > Yanmin
> > >
> > > > -Original Message-
> > > > From: Vivi, Rodrigo
> > > > Sent: Friday, November 30, 2018 1:45 AM
> > > > To: Zhang, Yanmin
> > > > Cc: Syrjala, Ville
> > > > Subject: Re: DP1.2 MST HUB
> > > >
> > > > Hi Yanmin,
> > > >
> > > > On Wed, Nov 28, 2018 at 05:03:02PM -0800, Zhang, Yanmin wrote:
> > > > >Dear GFX/display experts,
> > > >
> > > > maybe it would
