drm/i915/bios: throw away struct old_child_dev_config

The old_child_dev_config struct is no longer needed except for its size;
replace with a macro. No functional change.

Cc: Animesh Manna <animesh.manna@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: NVille Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: NJani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/4bfa6e45fecd33af797ec218635504ec8a09f788.1503600621.git.jani.nikula@intel.com

drivers/gpu/drm/i915/intel_bios.c

@@ -479,7 +479,7 @@ parse_sdvo_device_mapping(struct drm_i915_private *dev_priv,
 	 * device size matches that of the *legacy* child device config
 	 * struct. Thus, SDVO mapping will be skipped for newer VBT.
 	 */
-	if (p_defs->child_dev_size != sizeof(struct old_child_dev_config)) {
+	if (p_defs->child_dev_size != LEGACY_CHILD_DEVICE_CONFIG_SIZE) {
 		DRM_DEBUG_KMS("Unsupported child device size for SDVO mapping.\n");
 		return;
 	}
@@ -1267,8 +1267,7 @@ parse_device_mapping(struct drm_i915_private *dev_priv,
 	} else if (bdb->version < 111) {
 		expected_size = 27;
 	} else if (bdb->version < 195) {
-		BUILD_BUG_ON(sizeof(struct old_child_dev_config) != 33);
-		expected_size = sizeof(struct old_child_dev_config);
+		expected_size = LEGACY_CHILD_DEVICE_CONFIG_SIZE;
 	} else if (bdb->version == 195) {
 		expected_size = 37;
 	} else if (bdb->version <= 197) {
@@ -1286,7 +1285,7 @@ parse_device_mapping(struct drm_i915_private *dev_priv,
 			  p_defs->child_dev_size, expected_size, bdb->version);
 
 	/* The legacy sized child device config is the minimum we need. */
-	if (p_defs->child_dev_size < sizeof(struct old_child_dev_config)) {
+	if (p_defs->child_dev_size < LEGACY_CHILD_DEVICE_CONFIG_SIZE) {
 		DRM_DEBUG_KMS("Child device config size %u is too small.\n",
 			      p_defs->child_dev_size);
 		return;

drivers/gpu/drm/i915/intel_vbt_defs.h

@@ -230,32 +230,7 @@ struct bdb_general_features {
 #define DEVICE_PORT_DVOB	0x01
 #define DEVICE_PORT_DVOC	0x02
 
-/*
- * We used to keep this struct but without any version control. We should avoid
- * using it in the future, but it should be safe to keep using it in the old
- * code. Do not change; we rely on its size.
- */
-struct old_child_dev_config {
-	u16 handle;
-	u16 device_type;
-	u8  device_id[10]; /* ascii string */
-	u16 addin_offset;
-	u8  dvo_port; /* See Device_PORT_* above */
-	u8  i2c_pin;
-	u8  slave_addr;
-	u8  ddc_pin;
-	u16 edid_ptr;
-	u8  dvo_cfg; /* See DEVICE_CFG_* above */
-	u8  dvo2_port;
-	u8  i2c2_pin;
-	u8  slave2_addr;
-	u8  ddc2_pin;
-	u8  capabilities;
-	u8  dvo_wiring;/* See DEVICE_WIRE_* above */
-	u8  dvo2_wiring;
-	u16 extended_type;
-	u8  dvo_function;
-} __packed;
+#define LEGACY_CHILD_DEVICE_CONFIG_SIZE		33
 
 /*
  * The child device config, aka the display device data structure, provides a