Wavering Arrandale output

[Gustavo F. Padovan]

* Chris Wilson <chris at chris-wilson.co.uk> [2011-05-14 08:55:15 +0100]:

> On Fri, 13 May 2011 17:45:11 -0300, "Gustavo F. Padovan" <padovan at profusion.mobi> wrote:
> > Hi Chris,
> > 
> > Bug #28306 is going to complete his first birthday at the end of this month,
> > it is nagging around for a long time and I have many interest in fix this.
> > 
> > So I tested your patch in duplicated bug #36599 and it doesn't work, but I
> > managed to add some printks(see diff) there to help debug.
> > 
> > [    1.033866] [drm:intel_crtc_mode_set] *ERROR* 1. use_ssc 1
> > [    1.033868] [drm:intel_crtc_mode_set] *ERROR* encoder->type 4
> > [    1.033869] [drm:intel_crtc_mode_set] *ERROR* 2. use_ssc 1
> > [    1.034120] [drm:intel_crtc_mode_set] *ERROR* is_lvds 1
> > [    1.034121] [drm:intel_crtc_mode_set] *ERROR* has_edp_encoder
> > (null)
> > [    1.191465] [drm:intel_crtc_mode_set] *ERROR* 1. use_ssc 1
> > [    1.191466] [drm:intel_crtc_mode_set] *ERROR* encoder->type 4
> > [    1.191468] [drm:intel_crtc_mode_set] *ERROR* encoder->type 1
> > [    1.191469] [drm:intel_crtc_mode_set] *ERROR* 2. use_ssc 0
> > [    1.191720] [drm:intel_crtc_mode_set] *ERROR* is_lvds 0
> > [    1.191721] [drm:intel_crtc_mode_set] *ERROR* has_edp_encoder
> > (null)
> > 
> > It seems your patch has no effect once has_edp_encoder is null. Can you please
> > look into this? I can provide any test you may want, just send me the patches.
> > ;)
> 
> With no eDP on the system, we wouldn't expect to apply any of the eDP
> settings.
> 
> Even after your fix to the patch, nothing? Can you try just setting
> use_ssc=0 (and keep your fix).
> 
> In 633f2ea26665d37bb3c8ae30799aa14988622653 (drm/i915: Disable SSC for
> outputs other than LVDS or DP) I tried to implement another aspect of
> source-clock control, that is the patch that appeared to work if you only
> had VGA connected. So the next step would be to combine the two patches.

No fixes for this yet. There are many devices out there with this bug.
Can someone please take a look on this? Just send me patches, I can test them.

	Gustavo