Re: [2.6.39] drm/i915: blank screen on Lenovo Ideapad U160
From: Jesse Barnes
Date: Thu Jun 16 2011 - 14:42:03 EST
On Thu, 16 Jun 2011 19:54:36 +0200
Dirk Gouders <gouders@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> writes:
> > On Thu, 16 Jun 2011 13:49:11 +0200
> > Dirk Gouders <gouders@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> >> Some redundant information, but if I change one line at another place
> >> in the i915 code (whithout the above modification) the result is more
> >> satisfactory on my machine, because in that case the display even works
> >> after I close and reopen the lid:
> >> diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> >> index 927442a..ebb67ae 100644
> >> --- a/drivers/gpu/drm/i915/intel_bios.c
> >> +++ b/drivers/gpu/drm/i915/intel_bios.c
> >> @@ -267,7 +267,7 @@ static int intel_bios_ssc_frequency(struct drm_device *dev,
> >> case 4:
> >> return alternate ? 100 : 96;
> >> default:
> >> - return alternate ? 100 : 120;
> >> + return alternate ? 120 : 100;
> >> }
> >> }
> > Does your machine also work if you set the lvds_use_ssc param to 0?
> Yes, that works!
> I undid all modifications, compiled the i915 driver as a module (I am
> not sure if that is necessary) und used i915.lvds_use_ssc=0 as a
> further bootparameter, I will attach the dmesg output.
> Would you say "This problem was just a case of wrong parameter usage",
No, we should be parsing the VBT differently in your case it appears.
But the simple change above will break other platforms, so it's
possible we're missing a VBT format change and need to parse it
differently depending on the version.
Jesse Barnes, Intel Open Source Technology Center
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