[Intel-gfx] Sandy Bridge Desktop - 1920x1080i interlace not working

Daniel Vetter daniel at ffwll.ch
Thu Jan 19 13:12:35 CET 2012

On Thu, Jan 19, 2012 at 12:51:20PM +0100, Alfonso Fiore wrote:
> On Thu, Jan 19, 2012 at 12:32 PM, Daniel Vetter <daniel at ffwll.ch> wrote:
> >
> > Also please don't add any modes with xrandr (or in your xorg.conf) and try
> > to reset any other xrandr tools that might change your mode when logging
> > in. It's rather likely that your TV is really picky about the mode, so if
> > you don't get it exactly right it'll bail out. xrandr should show you all
> > the detected (and by i915 supported modes).
> Ok, so can you please tell me which are the right commands
> to list accepted resolutions and which command to switch?
> Maybe I misunderstand, but I should be able to run 1024x768 which is
> not interlaced.

As Peter said

$ xrandr -q

will show all modes detected and the current configuration. Then use the
normal xrandr commands to select your desired resolution. Also can you
attach full dmesg with drm.debug=0xe again, the one you've attached is
missing a few things at the top. Maybe your kernel dmesg buffer is too
small. You can adjust that size with log_buf_len=2M or so on the kernel

> > Also, can you describe "oddly placed" more precisely (maybe with a pic)?
> attached the two pictures of LightDM, with and without nomodeset with
> kernel keithp plus drm-intel-fixes (without Peter's patch for
> interlaced).

This looks like overscan/scaling-comp gone wrong (but I haven't ever seen
that in practice, so not much clue). Rodrigo is working on patches to add
support for overscan comp, maybe he has a few patches for you to try.

Daniel Vetter
Mail: daniel at ffwll.ch
Mobile: +41 (0)79 365 57 48

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