drm/i915/bios: abstract child device size check

Separate the child device size check to a separate function for
clarity. No functional changes.

Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240226175854.287871-2-jani.nikula@intel.com
Signed-off-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 f967ab406e353d51d44df4e522a839abc77c1554..c0f41bd1f9462d484a401ce30dd2f46b89e49660 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -2699,6 +2699,49 @@ static void parse_ddi_ports(struct drm_i915_private *i915)
                print_ddi_port(devdata);
 }
 
+static bool child_device_size_valid(struct drm_i915_private *i915, int size)
+{
+       int expected_size;
+
+       if (i915->display.vbt.version < 106) {
+               expected_size = 22;
+       } else if (i915->display.vbt.version < 111) {
+               expected_size = 27;
+       } else if (i915->display.vbt.version < 195) {
+               expected_size = LEGACY_CHILD_DEVICE_CONFIG_SIZE;
+       } else if (i915->display.vbt.version == 195) {
+               expected_size = 37;
+       } else if (i915->display.vbt.version <= 215) {
+               expected_size = 38;
+       } else if (i915->display.vbt.version <= 255) {
+               expected_size = 39;
+       } else if (i915->display.vbt.version <= 256) {
+               expected_size = 40;
+       } else {
+               expected_size = sizeof(struct child_device_config);
+               BUILD_BUG_ON(sizeof(struct child_device_config) < 40);
+               drm_dbg(&i915->drm,
+                       "Expected child device config size for VBT version %u not known; assuming %d\n",
+                       i915->display.vbt.version, expected_size);
+       }
+
+       /* Flag an error for unexpected size, but continue anyway. */
+       if (size != expected_size)
+               drm_err(&i915->drm,
+                       "Unexpected child device config size %d (expected %d for VBT version %u)\n",
+                       size, expected_size, i915->display.vbt.version);
+
+       /* The legacy sized child device config is the minimum we need. */
+       if (size < LEGACY_CHILD_DEVICE_CONFIG_SIZE) {
+               drm_dbg_kms(&i915->drm,
+                           "Child device config size %d is too small.\n",
+                           size);
+               return false;
+       }
+
+       return true;
+}
+
 static void
 parse_general_definitions(struct drm_i915_private *i915)
 {
@@ -2706,7 +2749,6 @@ parse_general_definitions(struct drm_i915_private *i915)
        struct intel_bios_encoder_data *devdata;
        const struct child_device_config *child;
        int i, child_device_num;
-       u8 expected_size;
        u16 block_size;
        int bus_pin;
 
@@ -2730,41 +2772,8 @@ parse_general_definitions(struct drm_i915_private *i915)
        if (intel_gmbus_is_valid_pin(i915, bus_pin))
                i915->display.vbt.crt_ddc_pin = bus_pin;
 
-       if (i915->display.vbt.version < 106) {
-               expected_size = 22;
-       } else if (i915->display.vbt.version < 111) {
-               expected_size = 27;
-       } else if (i915->display.vbt.version < 195) {
-               expected_size = LEGACY_CHILD_DEVICE_CONFIG_SIZE;
-       } else if (i915->display.vbt.version == 195) {
-               expected_size = 37;
-       } else if (i915->display.vbt.version <= 215) {
-               expected_size = 38;
-       } else if (i915->display.vbt.version <= 255) {
-               expected_size = 39;
-       } else if (i915->display.vbt.version <= 256) {
-               expected_size = 40;
-       } else {
-               expected_size = sizeof(*child);
-               BUILD_BUG_ON(sizeof(*child) < 40);
-               drm_dbg(&i915->drm,
-                       "Expected child device config size for VBT version %u not known; assuming %u\n",
-                       i915->display.vbt.version, expected_size);
-       }
-
-       /* Flag an error for unexpected size, but continue anyway. */
-       if (defs->child_dev_size != expected_size)
-               drm_err(&i915->drm,
-                       "Unexpected child device config size %u (expected %u for VBT version %u)\n",
-                       defs->child_dev_size, expected_size, i915->display.vbt.version);
-
-       /* The legacy sized child device config is the minimum we need. */
-       if (defs->child_dev_size < LEGACY_CHILD_DEVICE_CONFIG_SIZE) {
-               drm_dbg_kms(&i915->drm,
-                           "Child device config size %u is too small.\n",
-                           defs->child_dev_size);
+       if (!child_device_size_valid(i915, defs->child_dev_size))
                return;
-       }
 
        /* get the number of child device */
        child_device_num = (block_size - sizeof(*defs)) / defs->child_dev_size;