On 13 September 2016 at 10:22, <ville.syrjala@xxxxxxxxxxxxxxx> wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > Turns out > commit a05628195a0d ("drm/i915: Get panel_type from OpRegion panel > details") has regressed quite a few machines. So it looks like we > can't use the panel type from OpRegion on all systems, and yet we > absolutely must use it on some specific systems. > > Despite trying, I was unable to find any automagic way to determine > if the OpRegion panel type is respectable or not. The only glimmer > of hope I had was bit 8 in the SCIC response, but that turned out to > not work either (it was always 0 on both types of systems). > > So, to fix the regressions without breaking the machine we know to need > the OpRegion panel type, let's just add a quirk for this. Only specific > machines known to require the OpRegion panel type will therefore use > it. Everyone else will fall bck to the VBT panel type. > > The only known machine so far is a "Conrac GmbH IX45GM2". The PCI > subsystem ID on this machine is just a generic 8086:2a42, so of no use. > Instead we'll go with a DMI match. > > I suspect we can now also revert > commit aeddda06c1a7 ("drm/i915: Ignore panel type from OpRegion on SKL") > but let's leave that to a separate patch. > > v2: Do the DMI match in the opregion code directly, as dev_priv->quirks > gets populated too late > > Cc: Rob Kramer <rob@xxxxxxxxxxxxxxxxxx> > Cc: Martin van Es <martin@xxxxxxxxxxx> > Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> > Cc: Dave Airlie <airlied@xxxxxxxx> > Cc: Marco Krüger <krgsch@xxxxxxxxx> > Cc: Sean Greenslade <sean@xxxxxxxxxxxxxxxxxx> > Cc: Trudy Tective <bertslany@xxxxxxxxx> > Cc: Robin Müller <rm1990@xxxxxx> > Cc: Alexander Kobel <a-kobel@xxxxxxxxxx> > Cc: Alexey Shumitsky <alexey.shumitsky@xxxxxxxxx> > Cc: Emil Andersen Lauridsen <mine809@xxxxxxxxx> > Cc: oceans112@xxxxxxxxx > Cc: James Hogan <james@xxxxxxxxxxxxx> > Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx > References: https://lists.freedesktop.org/archives/intel-gfx/2016-August/105545.html > References: https://lists.freedesktop.org/archives/dri-devel/2016-August/116888.html > References: https://lists.freedesktop.org/archives/intel-gfx/2016-June/098826.html > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=94825 > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97060 > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97443 > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=97363 > Fixes: a05628195a0d ("drm/i915: Get panel_type from OpRegion panel details") > Tested-by: Marco Krüger <krgsch@xxxxxxxxx> > Tested-by: Alexey Shumitsky <alexey.shumitsky@xxxxxxxxx> > Tested-by: Sean Greenslade <sean@xxxxxxxxxxxxxxxxxx> > Tested-by: Emil Andersen Lauridsen <mine809@xxxxxxxxx> > Tested-by: Robin Müller <rm1990@xxxxxx> > Tested-by: oceans112@xxxxxxxxx > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> That works for me too on XPS13. Flickering screen brightness gone, and using acpi backlight rather than intel backlight, like before a05628195a0d ("drm/i915: Get panel_type from OpRegion panel details"). Tested-by: James Hogan <james@xxxxxxxxxxxxx> Thanks! James > --- > drivers/gpu/drm/i915/intel_opregion.c | 27 +++++++++++++++++++++++++++ > 1 file changed, 27 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_opregion.c b/drivers/gpu/drm/i915/intel_opregion.c > index adca262d591a..7acbbbf97833 100644 > --- a/drivers/gpu/drm/i915/intel_opregion.c > +++ b/drivers/gpu/drm/i915/intel_opregion.c > @@ -1047,6 +1047,23 @@ err_out: > return err; > } > > +static int intel_use_opregion_panel_type_callback(const struct dmi_system_id *id) > +{ > + DRM_INFO("Using panel type from OpRegion on %s\n", id->ident); > + return 1; > +} > + > +static const struct dmi_system_id intel_use_opregion_panel_type[] = { > + { > + .callback = intel_use_opregion_panel_type_callback, > + .ident = "Conrac GmbH IX45GM2", > + .matches = {DMI_MATCH(DMI_SYS_VENDOR, "Conrac GmbH"), > + DMI_MATCH(DMI_PRODUCT_NAME, "IX45GM2"), > + }, > + }, > + { } > +}; > + > int > intel_opregion_get_panel_type(struct drm_i915_private *dev_priv) > { > @@ -1073,6 +1090,16 @@ intel_opregion_get_panel_type(struct drm_i915_private *dev_priv) > } > > /* > + * So far we know that some machined must use it, others must not use it. > + * There doesn't seem to be any way to determine which way to go, except > + * via a quirk list :( > + */ > + if (!dmi_check_system(intel_use_opregion_panel_type)) { > + DRM_DEBUG_KMS("Ignoring OpRegion panel type (%d)\n", ret - 1); > + return -ENODEV; > + } > + > + /* > * FIXME On Dell XPS 13 9350 the OpRegion panel type (0) gives us > * low vswing for eDP, whereas the VBT panel type (2) gives us normal > * vswing instead. Low vswing results in some display flickers, so > -- > 2.7.4 > -- James Hogan _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx