Re: r277959 breaks X display on IvyBridge mobile GT2 IG

Adrian Chadd wrote:
> Hi,
> 
> There's a "invert backlight" option in i915, try setting it to 1?

This is pretty much all I could find (unless I was looking in the
wrong place).  It makes no difference.  The backlight appears to
be disabled.

Index: intel_display.c
===================================================================
--- intel_display.c     (revision 278584)
+++ intel_display.c     (working copy)
_at__at_ -6938,6 +6938,9 _at__at_
 
        /* Acer Aspire 5734Z must invert backlight brightness */
        { 0x2a42, 0x1025, 0x0459, quirk_invert_brightness },
+
+       /* Asus Zenbook UX31A must invert backlight brightness */
+       { 0x0166, 0x1043, 0x1517, quirk_invert_brightness },
 };
 
 static void intel_init_quirks(struct drm_device *dev)


Resulting log message:
Feb 11 11:55:38 zen kernel: info: [drm] applying inverted panel brightness quirk

The flag removed by r278584 is BLM_PCH_OVERRIDE_ENABLE according
to the Linux driver.  I think we're not correctly setting or selecting
the PWM channel for backlight control.

> 
> -a
> 
> 
> On 11 February 2015 at 07:41, Ian FREISLICH <ianf_at_capeaugusta.com> wrote:
> > Hi
> >
> > With this commit my display blanks and never lights up when X starts.
> >
> > [zen] /usr/src # svn diff -r 277958:277959
> > Index: sys/dev/drm2/i915/intel_display.c
> > ===================================================================
> > --- sys/dev/drm2/i915/intel_display.c   (revision 277958)
> > +++ sys/dev/drm2/i915/intel_display.c   (revision 277959)
> > _at__at_ -6995,7 +6995,7 _at__at_
> >          */
> >         I915_WRITE(BLC_PWM_CPU_CTL2, PWM_ENABLE);
> >         I915_WRITE(BLC_PWM_CPU_CTL, 0);
> > -       I915_WRITE(BLC_PWM_PCH_CTL1, PWM_ENABLE | (1<<30));
> > +       I915_WRITE(BLC_PWM_PCH_CTL1, PWM_ENABLE);
> >  }
> >
> >  void intel_modeset_init_hw(struct drm_device *dev)
> >
> >
> > vgapci0_at_pci0:0:2:0:     class=0x030000 card=0x15171043 chip=0x01668086 rev=
0x09
> > hdr=0x00
> >     vendor     = 'Intel Corporation'
> >     device     = '3rd Gen Core processor Graphics Controller'
> >     class      = display
> >     subclass   = VGA
> >     cap 05[90] = MSI supports 1 message enabled with 1 message
> >     cap 01[d0] = powerspec 2  supports D0 D3  current D0
> >     cap 13[a4] = PCI Advanced Features: FLR TP
> >
> > Ian
> >
> > --
> > Ian Freislich
> > _______________________________________________
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> > http://lists.freebsd.org/mailman/listinfo/freebsd-current
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-- 
Meditating Guru
Ian Freislich