[PATCH v2] drm/TODO: Add vrefresh replacement to the todo

[Sean Paul]

From: Sean Paul <seanpaul at chromium.org>

Changes in v2:
- Add drm_display_mode.vrefresh removal (Ville)
- Add Sam's R-b and bonus points

Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Suggested-by: Daniel Vetter <daniel at ffwll.ch>
Reviewed-by: Sam Ravnborg <sam at ravnborg.org>
Bonus-points-awarded-by: Sam Ravnborg <sam at ravnborg.org>
Signed-off-by: Sean Paul <seanpaul at chromium.org>
---
 Documentation/gpu/todo.rst | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index 38360ede12215..1bbfc5e1b2a46 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -262,6 +262,24 @@ As a reference, take a look at the conversions already completed in drm core.
 
 Contact: Sean Paul, respective driver maintainers
 
+Convert direct mode.vrefresh accesses to use drm_mode_vrefresh()
+----------------------------------------------------------------
+
+drm_display_mode.vrefresh isn't guaranteed to be populated. As such, using it
+is risky and has been known to cause div-by-zero bugs. Fortunately, drm core
+has helper which will use mode.vrefresh if it's !0 and will calculate it from
+the timings when it's 0.
+
+Use simple search/replace, or (more fun) cocci to replace instances of direct
+vrefresh access with a call to the helper. Check out
+https://lists.freedesktop.org/archives/dri-devel/2019-January/205186.html for
+inspiration.
+
+Once all instances of vrefresh have been converted, consider removing vrefresh
+from drm_display_mode to avoid future use.
+
+Contact: Sean Paul
+
 Core refactorings
 =================
 
-- 
Sean Paul, Software Engineer, Google / Chromium OS