On Thu, Oct 09, 2014 at 07:37:15PM +0300, ville.syrjala@xxxxxxxxxxxxxxx wrote: > From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> > > On CHV the display DDC pins may be muxed to an alternate function if > there's no need for DDC on a specific port, which is the case for eDP > ports since there's no way to plug in a DP++ HDMI dongle. > > This causes problems when trying to determine if the port is present > since the the DP_DETECTED bit is the latched state of the DDC SDA pin > at boot. If the DDC pins are muxed to an alternate function the bit > may indicate that the port isn't present. > > To work around this look at the VBT as well as the DP_DETECTED bit > to determine if we should attempt registering an eDP port. Do this > only for ports B and C since port D doesn't support eDP (no PPS/BLC). > > In theory someone could also wire up a normal DP port w/o DDC lines. > That would just mean that simple DP++ HDMI dongles wouldn't work > on such a port. With this change we would still fail to register > such DP ports. But let's hope no one wires their board in such a way, > and if they do we can extend the VBT checks to cover normal DP ports > as well. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=84265 > Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Reviewed-by: Damien Lespiau <damien.lespiau@xxxxxxxxx> -- Damien > --- > drivers/gpu/drm/i915/intel_display.c | 33 +++++++++++++++++++++------------ > 1 file changed, 21 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c > index b5476dc..d6fc469 100644 > --- a/drivers/gpu/drm/i915/intel_display.c > +++ b/drivers/gpu/drm/i915/intel_display.c > @@ -12280,27 +12280,36 @@ static void intel_setup_outputs(struct drm_device *dev) > if (I915_READ(PCH_DP_D) & DP_DETECTED) > intel_dp_init(dev, PCH_DP_D, PORT_D); > } else if (IS_VALLEYVIEW(dev)) { > - if (I915_READ(VLV_DISPLAY_BASE + GEN4_HDMIB) & SDVO_DETECTED) { > + /* > + * The DP_DETECTED bit is the latched state of the DDC > + * SDA pin at boot. However since eDP doesn't require DDC > + * (no way to plug in a DP->HDMI dongle) the DDC pins for > + * eDP ports may have been muxed to an alternate function. > + * Thus we can't rely on the DP_DETECTED bit alone to detect > + * eDP ports. Consult the VBT as well as DP_DETECTED to > + * detect eDP ports. > + */ > + if (I915_READ(VLV_DISPLAY_BASE + GEN4_HDMIB) & SDVO_DETECTED) > intel_hdmi_init(dev, VLV_DISPLAY_BASE + GEN4_HDMIB, > PORT_B); > - if (I915_READ(VLV_DISPLAY_BASE + DP_B) & DP_DETECTED) > - intel_dp_init(dev, VLV_DISPLAY_BASE + DP_B, PORT_B); > - } > + if (I915_READ(VLV_DISPLAY_BASE + DP_B) & DP_DETECTED || > + intel_dp_is_edp(dev, PORT_B)) > + intel_dp_init(dev, VLV_DISPLAY_BASE + DP_B, PORT_B); > > - if (I915_READ(VLV_DISPLAY_BASE + GEN4_HDMIC) & SDVO_DETECTED) { > + if (I915_READ(VLV_DISPLAY_BASE + GEN4_HDMIC) & SDVO_DETECTED) > intel_hdmi_init(dev, VLV_DISPLAY_BASE + GEN4_HDMIC, > PORT_C); > - if (I915_READ(VLV_DISPLAY_BASE + DP_C) & DP_DETECTED) > - intel_dp_init(dev, VLV_DISPLAY_BASE + DP_C, PORT_C); > - } > + if (I915_READ(VLV_DISPLAY_BASE + DP_C) & DP_DETECTED || > + intel_dp_is_edp(dev, PORT_C)) > + intel_dp_init(dev, VLV_DISPLAY_BASE + DP_C, PORT_C); > > if (IS_CHERRYVIEW(dev)) { > - if (I915_READ(VLV_DISPLAY_BASE + CHV_HDMID) & SDVO_DETECTED) { > + if (I915_READ(VLV_DISPLAY_BASE + CHV_HDMID) & SDVO_DETECTED) > intel_hdmi_init(dev, VLV_DISPLAY_BASE + CHV_HDMID, > PORT_D); > - if (I915_READ(VLV_DISPLAY_BASE + DP_D) & DP_DETECTED) > - intel_dp_init(dev, VLV_DISPLAY_BASE + DP_D, PORT_D); > - } > + /* eDP not supported on port D, so don't check VBT */ > + if (I915_READ(VLV_DISPLAY_BASE + DP_D) & DP_DETECTED) > + intel_dp_init(dev, VLV_DISPLAY_BASE + DP_D, PORT_D); > } > > intel_dsi_init(dev); > -- > 2.0.4 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
