drm/i915: Annotate more of the BIOS fb takeover failure paths

Annotate a few more of the failure paths on the initial
BIOS fb takeover to avoid having to guess why things
aren't working the way we expect.
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Tested-by: Paz Zcharya <pazz@chromium.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240202224340.30647-17-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/display/intel_plane_initial.c

@@ -167,14 +167,19 @@ initial_plane_vma(struct drm_i915_private *i915,
 	 */
 	if (IS_ENABLED(CONFIG_FRAMEBUFFER_CONSOLE) &&
 	    mem == i915->mm.stolen_region &&
-	    size * 2 > i915->dsm.usable_size)
+	    size * 2 > i915->dsm.usable_size) {
+		drm_dbg_kms(&i915->drm, "Initial FB size exceeds half of stolen, discarding\n");
 		return NULL;
+	}
 
 	obj = i915_gem_object_create_region_at(mem, phys_base, size,
 					       I915_BO_ALLOC_USER |
 					       I915_BO_PREALLOC);
-	if (IS_ERR(obj))
+	if (IS_ERR(obj)) {
+		drm_dbg_kms(&i915->drm, "Failed to preallocate initial FB in %s\n",
+			    mem->region.name);
 		return NULL;
+	}
 
 	/*
 	 * Mark it WT ahead of time to avoid changing the