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> --- 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
