Re: Sandy Bridge Desktop - 1920x1080i interlace not working

[Daniel Vetter <daniel@ffwll.ch>]

On Wed, Jan 18, 2012 at 09:44:51PM +0100, Alfonso Fiore wrote:
> On Wed, Jan 18, 2012 at 9:12 PM, Daniel Vetter <daniel@ffwll.ch> wrote:
> > On Wed, Jan 18, 2012 at 05:08:55PM +0100, Alfonso Fiore wrote:
> >> On Tue, Jan 17, 2012 at 10:34 PM, Daniel Vetter <daniel@ffwll.ch> wrote:
> >> >
> >> > On Tue, Jan 17, 2012 at 09:59:18PM +0100, Alfonso Fiore wrote:
> >> > > Hi,
> >> > >
> >> > > here is mine. Let me know if you need any other log.
> >> >
> >> > Ok, your TV only reports 1080i as a mode (at least that's the only thing
> >> > your kernel can decode). The i915 driver then rejects it because it's
> >> > interlaced (we unfortunately do not yet support interlaced everywhere we
> >> > could). Which leaves you with no modes, so as a fallback the kernel just
> >> > adds a bunch of default VGA modes which your TV can't cope with properly.
> >>
> >> Hi Daniel,
> >>
> >> would you agree that these are two separate bugs?
> >> I'd like the Intel driver to both:
> >> - allow me to use 1920x1080i
> >> - allow me to use 1024x768p without reverting to nomodeset
> >
> > Yep, that's correct. For the first issue Peter Ross is working on some
> > patches, for the later I suspect the missing CEA support. Please try this
> > out by grabbing the kernel tree I've told you and running it. Peter's
> > patches are on this mailing list, if it's easier for you I could create a
> > quick git branch somewhere.
> >
> >> If I want to see a video where a progressive resolution brings better
> >> results than an interlaced resolution (despite the less pixels) I'd
> >> like to be able to.
> >>
> >> Right now, with nomodeset I can only play video using VLC which has
> >> its own hardware acceleration. With the embedded xbmc player I can't
> >> watch any video.
> >>
> >> Will a proper way to see 1024x768 be added? kernel 3.0.0-12.20 (Ubuntu
> >> 11.10) was working fine with the i3 550.
> >
> > Hm, that smells like a regression. Was this also with nomodeset?
> 
> Hi Daniel,
> 
> I'm 100% sure that it was without nomodeset since I didn't reinstalled
> Ubuntu when I changed MB. Everything was exactly the same
> (except for MB and CPU) and I turned it on and had this problem.
> More than that, Ubuntu 11.10 installation was fine with i3 550 but it
> shows the bug with i3 2130.
> 
> So, if it's the same code, then I think it is a case of regression.

In that case actually, no. With nomodeset your using the vesa driver which
uses bios calls to change the resolution. You've changed the bios with the
mb. One of the reasons kms was created is to avoid such issues ;-)
-Daniel
-- 
Daniel Vetter
Mail: daniel@ffwll.ch
Mobile: +41 (0)79 365 57 48