drm/i915: Clean up DDI DDC/AUX CH sanitation

Now that we use the AUX and GMBUS assignment from VBT for all ports,
let's clean up the sanitization of the port information a bit.
Previosuly we only did this for port E, and only complained about a
non-standard assignment for the other ports. But as we know that
non-standard assignments are a fact of life, let's expand the
sanitization to all the ports.

v2: Include a commit message, fix up the comments a bit
v3: Don't clobber other ports if the current port has no alternate aux ch/ddc pin

Cc: stable@vger.kernel.org
Cc: Maarten Maathuis <madman2003@gmail.com>
Tested-by: Maarten Maathuis <madman2003@gmail.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=97877
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1476208368-5710-4-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Jim Bride <jim.bride@linux.intel.com> (v2)

1 files changed, 77 insertions, 45 deletions

diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
index 32e1def6a9ef..5ab646ef8c9f 100644
--- a/drivers/gpu/drm/i915/intel_bios.c
+++ b/drivers/gpu/drm/i915/intel_bios.c
@@ -1035,6 +1035,77 @@ static u8 translate_iboost(u8 val)
         return mapping[val];
 }
 
+static void sanitize_ddc_pin(struct drm_i915_private *dev_priv,
+                             enum port port)
+{
+        const struct ddi_vbt_port_info *info =
+                &dev_priv->vbt.ddi_port_info[port];
+        enum port p;
+
+        if (!info->alternate_ddc_pin)
+                return;
+
+        for_each_port_masked(p, (1 << port) - 1) {
+                struct ddi_vbt_port_info *i = &dev_priv->vbt.ddi_port_info[p];
+
+                if (info->alternate_ddc_pin != i->alternate_ddc_pin)
+                        continue;
+
+                DRM_DEBUG_KMS("port %c trying to use the same DDC pin (0x%x) as port %c, "
+                              "disabling port %c DVI/HDMI support\n",
+                              port_name(p), i->alternate_ddc_pin,
+                              port_name(port), port_name(p));
+
+                /*
+                 * If we have multiple ports supposedly sharing the
+                 * pin, then dvi/hdmi couldn't exist on the shared
+                 * port. Otherwise they share the same ddc bin and
+                 * system couldn't communicate with them separately.
+                 *
+                 * Due to parsing the ports in alphabetical order,
+                 * a higher port will always clobber a lower one.
+                 */
+                i->supports_dvi = false;
+                i->supports_hdmi = false;
+                i->alternate_ddc_pin = 0;
+        }
+}
+
+static void sanitize_aux_ch(struct drm_i915_private *dev_priv,
+                            enum port port)
+{
+        const struct ddi_vbt_port_info *info =
+                &dev_priv->vbt.ddi_port_info[port];
+        enum port p;
+
+        if (!info->alternate_aux_channel)
+                return;
+
+        for_each_port_masked(p, (1 << port) - 1) {
+                struct ddi_vbt_port_info *i = &dev_priv->vbt.ddi_port_info[p];
+
+                if (info->alternate_aux_channel != i->alternate_aux_channel)
+                        continue;
+
+                DRM_DEBUG_KMS("port %c trying to use the same AUX CH (0x%x) as port %c, "
+                              "disabling port %c DP support\n",
+                              port_name(p), i->alternate_aux_channel,
+                              port_name(port), port_name(p));
+
+                /*
+                 * If we have multiple ports supposedlt sharing the
+                 * aux channel, then DP couldn't exist on the shared
+                 * port. Otherwise they share the same aux channel
+                 * and system couldn't communicate with them separately.
+                 *
+                 * Due to parsing the ports in alphabetical order,
+                 * a higher port will always clobber a lower one.
+                 */
+                i->supports_dp = false;
+                i->alternate_aux_channel = 0;
+        }
+}
+
 static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
                            const struct bdb_header *bdb)
 {
@@ -1109,54 +1180,15 @@ static void parse_ddi_port(struct drm_i915_private *dev_priv, enum port port,
                 DRM_DEBUG_KMS("Port %c is internal DP\n", port_name(port));
 
         if (is_dvi) {
-                if (port == PORT_E) {
-                        info->alternate_ddc_pin = ddc_pin;
-                        /* if DDIE share ddc pin with other port, then
-                         * dvi/hdmi couldn't exist on the shared port.
-                         * Otherwise they share the same ddc bin and system
-                         * couldn't communicate with them seperately. */
-                        if (ddc_pin == DDC_PIN_B) {
-                                dev_priv->vbt.ddi_port_info[PORT_B].supports_dvi = 0;
-                                dev_priv->vbt.ddi_port_info[PORT_B].supports_hdmi = 0;
-                        } else if (ddc_pin == DDC_PIN_C) {
-                                dev_priv->vbt.ddi_port_info[PORT_C].supports_dvi = 0;
-                                dev_priv->vbt.ddi_port_info[PORT_C].supports_hdmi = 0;
-                        } else if (ddc_pin == DDC_PIN_D) {
-                                dev_priv->vbt.ddi_port_info[PORT_D].supports_dvi = 0;
-                                dev_priv->vbt.ddi_port_info[PORT_D].supports_hdmi = 0;
-                        }
-                } else if (ddc_pin == DDC_PIN_B && port != PORT_B)
-                        DRM_DEBUG_KMS("Unexpected DDC pin for port B\n");
-                else if (ddc_pin == DDC_PIN_C && port != PORT_C)
-                        DRM_DEBUG_KMS("Unexpected DDC pin for port C\n");
-                else if (ddc_pin == DDC_PIN_D && port != PORT_D)
-                        DRM_DEBUG_KMS("Unexpected DDC pin for port D\n");
+                info->alternate_ddc_pin = ddc_pin;
+
+                sanitize_ddc_pin(dev_priv, port);
         }
 
         if (is_dp) {
-                if (port == PORT_E) {
-                        info->alternate_aux_channel = aux_channel;
-                        /* if DDIE share aux channel with other port, then
-                         * DP couldn't exist on the shared port. Otherwise
-                         * they share the same aux channel and system
-                         * couldn't communicate with them seperately. */
-                        if (aux_channel == DP_AUX_A)
-                                dev_priv->vbt.ddi_port_info[PORT_A].supports_dp = 0;
-                        else if (aux_channel == DP_AUX_B)
-                                dev_priv->vbt.ddi_port_info[PORT_B].supports_dp = 0;
-                        else if (aux_channel == DP_AUX_C)
-                                dev_priv->vbt.ddi_port_info[PORT_C].supports_dp = 0;
-                        else if (aux_channel == DP_AUX_D)
-                                dev_priv->vbt.ddi_port_info[PORT_D].supports_dp = 0;
-                }
-                else if (aux_channel == DP_AUX_A && port != PORT_A)
-                        DRM_DEBUG_KMS("Unexpected AUX channel for port A\n");
-                else if (aux_channel == DP_AUX_B && port != PORT_B)
-                        DRM_DEBUG_KMS("Unexpected AUX channel for port B\n");
-                else if (aux_channel == DP_AUX_C && port != PORT_C)
-                        DRM_DEBUG_KMS("Unexpected AUX channel for port C\n");
-                else if (aux_channel == DP_AUX_D && port != PORT_D)
-                        DRM_DEBUG_KMS("Unexpected AUX channel for port D\n");
+                info->alternate_aux_channel = aux_channel;
+
+                sanitize_aux_ch(dev_priv, port);
         }
 
         if (bdb->version >= 158) {