drm/i915/bios: Use i915->vbt.ports[] on CHV

CHV is currently straddling the divide by using parse_ddi_ports() stuff
for aux_ch/ddc_pin but going through all old codepaths for the rest
(intel_bios_is_port_present(), intel_bios_is_port_edp(),
intel_bios_is_port_dp_dual_mode()). Let's switch over full and use
i915->vbt.ports[] for the rest of the stuff.

dvo_port_to_port() doesn't know about DSI so we won't get into
any kind of "is port B HDMI or DSI or both?" conundrum, which
could otherwise happen on VLV/CHV due to DSI ports living in a
separate world from the other digital ports.

Including Jani's detailed analysis here for posterity:
"We stop checking for port A for CHV in intel_bios_is_port_present(), but
 it's a warn and I don't recall any bug reports, so probably fine. We
 could add a check in parse_ddi_port(), but meh.

 Ditto for intel_bios_is_port_dp_dual_mode(), except it doesn't have a
 warn.

 The eDP check in intel_bios_is_port_edp() becomes slightly more
 relaxed. Both the old and new check require these to be set:

 - DEVICE_TYPE_DISPLAYPORT_OUTPUT
 - DEVICE_TYPE_INTERNAL_CONNECTOR.

 The old code also required these to be unset:

 - DEVICE_TYPE_MIPI_OUTPUT
 - DEVICE_TYPE_COMPOSITE_OUTPUT
 - DEVICE_TYPE_DUAL_CHANNEL
 - DEVICE_TYPE_LVDS_SIGNALING
 - DEVICE_TYPE_TMDS_DVI_SIGNALING
 - DEVICE_TYPE_VIDEO_SIGNALING
 - DEVICE_TYPE_ANALOG_OUTPUT

 It's possible we've added these just as a sanity check for broken VBTs
 more than anything. I guess I'd see if actual problems arise.

 Bottom line, I think the functional changes matter only for VBTs with
 bogus data."

I agree that it should work assuming the VBT isn't totally insane.
Modern windows drivers also don't seem to check any of those
additional device type bits, which may or may not matter for older
devices (no idea what some old driver versions are checking).

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211217155403.31477-3-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index e9b6b6e..3c4165d 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -2055,14 +2055,14 @@ static void parse_ddi_port(struct drm_i915_private *i915,
 
 static bool has_ddi_port_info(struct drm_i915_private *i915)
 {
-       return HAS_DDI(i915);
+       return HAS_DDI(i915) || IS_CHERRYVIEW(i915);
 }
 
 static void parse_ddi_ports(struct drm_i915_private *i915)
 {
        struct intel_bios_encoder_data *devdata;
 
-       if (!HAS_DDI(i915) && !IS_CHERRYVIEW(i915))
+       if (!has_ddi_port_info(i915))
                return;
 
        if (i915->vbt.version < 155)