[PATCH 4/4] drm/i915: Throw away the BIOS fb if has the wrong depth/bpp

[Ville Syrjala]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Respect the user's choice of depth/bpp for the fbdev framebuffer
and throw out the fb we inherited from the BIOS if it doesn't
match.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_fbdev.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
index 0d3a6fa674e6..1a935dc74d23 100644
--- a/drivers/gpu/drm/i915/intel_fbdev.c
+++ b/drivers/gpu/drm/i915/intel_fbdev.c
@@ -199,6 +199,17 @@ static int intelfb_create(struct drm_fb_helper *helper,
 		drm_framebuffer_put(&intel_fb->base);
 		intel_fb = ifbdev->fb = NULL;
 	}
+	if (intel_fb &&
+	    (sizes->surface_depth != intel_fb->base.format->depth ||
+	     sizes->surface_bpp != intel_fb->base.format->cpp[0] * 8)) {
+		DRM_DEBUG_KMS("BIOS fb using wrong depth/bpp (%d/%d), we require (%d/%d),"
+			      " releasing it\n",
+			      intel_fb->base.format->depth,
+			      intel_fb->base.format->cpp[0] * 8,
+			      sizes->surface_depth, sizes->surface_bpp);
+		drm_framebuffer_put(&intel_fb->base);
+		intel_fb = ifbdev->fb = NULL;
+	}
 	if (!intel_fb || WARN_ON(!intel_fb_obj(&intel_fb->base))) {
 		DRM_DEBUG_KMS("no BIOS fb, allocating a new one\n");
 		ret = intelfb_alloc(helper, sizes);
-- 
2.21.0