On Fri, 07 Nov 2014, ville.syrjala@xxxxxxxxxxxxxxx wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > When the display is off, we can't read out the current backlight level > from the hardware since we have no pipe to do so. Catch the INVALID_PIPE > in vlv_get_backlight() rather than pass it to VLV_BLC_PWM_CTL() which > would obviously end accessing some bogus register. > > This problem can be reproduced simply by reading the backlight device > actual_brightness file while the display is off. I think we should check for panel->backlight.enabled in intel_panel_get_backlight instead. I think it would be the right thing to do independent of the issue you found, but I think it also fixes your issue. BR, Jani. > > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_panel.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c > index ef646b1..847d00f9 100644 > --- a/drivers/gpu/drm/i915/intel_panel.c > +++ b/drivers/gpu/drm/i915/intel_panel.c > @@ -532,6 +532,9 @@ static u32 vlv_get_backlight(struct intel_connector *connector) > struct drm_device *dev = connector->base.dev; > enum pipe pipe = intel_get_pipe_from_connector(connector); > > + if (pipe == INVALID_PIPE) > + return 0; > + > return _vlv_get_backlight(dev, pipe); > } > > -- > 2.0.4 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
