drm/fb-helper: Add a FIXME that generic_setup is very confusing

I tried to fix this for real, but it's very sprawling and lots of
drivers get this mildly wrong one way or the other.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Acked-by: Simon Ser <contact@emersion.fr>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20201211161113.3350061-2-daniel.vetter@ffwll.ch

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 5ad19785daee26ef4b0e1bbb4abb0c813ad349b9..a44c3a4380592746ccb57ff33f68a1d3c2e797a6 100644 (file)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2496,6 +2496,11 @@ void drm_fbdev_generic_setup(struct drm_device *dev,
                return;
        }
 
+       /*
+        * FIXME: This mixes up depth with bpp, which results in a glorious
+        * mess, resulting in some drivers picking wrong fbdev defaults and
+        * others wrong preferred_depth defaults.
+        */
        if (!preferred_bpp)
                preferred_bpp = dev->mode_config.preferred_depth;
        if (!preferred_bpp)