Re: bad panel power sequencing delays, disabling panel

[Seth Forshee <seth.forshee@canonical.com>]

On Wed, Oct 24, 2012 at 10:03:12AM +0200, Daniel Vetter wrote:
> On Wed, Oct 24, 2012 at 01:27:23PM +0800, Daniel J Blueman wrote:
> > On 17 October 2012 00:43, Daniel Vetter <daniel@ffwll.ch> wrote:
> > > On Tue, Oct 16, 2012 at 6:10 PM, Daniel J Blueman <daniel@quora.org> wrote:
> > >> [drm:intel_dp_init], cur t1_t3 0 t8 0 t9 0 t10 0 t11_t12 4000
> > >> [drm:intel_dp_init], vbt t1_t3 0 t8 0 t9 0 t10 0 t11_t12 0
> > >> [drm:intel_dp_init], panel power up delay 21, power down delay 50,
> > >> power cycle delay 400
> > >> [drm:intel_dp_init], backlight on delay 5, off delay 5
> > >> [drm:intel_dp_init], panel power sequencer register settings: PP_ON
> > >> 0x40d20032, PP_OFF 0x1f40032, PP_DIV 0x186904
> > >> [drm:intel_dp_i2c_init], i2c_init DPDDC-A
> > >> [drm:ironlake_edp_panel_vdd_on], Turn eDP VDD on
> > >> [drm:ironlake_edp_panel_vdd_on], eDP VDD already on
> > >> [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x514500c8
> > >> [drm:intel_dp_i2c_aux_ch], aux_ch failed -110
> > >>
> > >> Notable, the nvidia DP init script executed fine; perhaps tracing the
> > >> I2C access may be useful?
> > >
> > > Hm, dp aux transfer don't work (this is the first one in the setup
> > > sequence, so it's not an i2c over aux issue with the edid read). I
> > > guess the mux is getting in the way. Dave, do you have an idea what's
> > > still going wrong? panel power sequence is now operationl. For
> > > reference, the wip patch series is at:
> > > http://cgit.freedesktop.org/~danvet/drm/log/?h=for-pzanoni
> > 
> > Booting for-pzanoni as of today, when switching to i915, the backlight
> > turns off [1]. Full boot log at
> > http://quora.org/2012/mbp-i915-panel-3.txt ; the same situation occurs
> > on 3.7-rc2 alas.
> 
> Yeah, you have an issue with dp aux not working (since the mux is set
> wrongly), not with the panel not being powered on (or at least that's a
> secondary issue). So the panel power improvements don't help you.

My suspicion is that Daniel has been using the technique of setting the
mux to the integrated GPU in OS X and rebooting, which I've heard others
say works. Likely the new firmware now resets the mux to the DGPU when
the machine reboots.

> > Is there a way to trigger re-enumeration of the panels after I
> > switcheroo to i915?
> > 
> > I'm checking with Seth if the mux could be the issue, though the code
> > shows there would be an error message if switching failed.
> 
> Iirc Dave Airlie has patches to delay the driver init until the mux code
> is all set up, so that the driver could request the mux to be switched
> while init is ongoing.

Actually those were my patches, which Dave rejected. I haven't had the
time yet to try and find yet another way of getting switcheroo to work
on these machines.

Seth