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

[Sam Ravnborg <sam@ravnborg.org>]

On Tue, Jan 29, 2019 at 11:15:51AM -0500, Sean Paul wrote:
> From: Sean Paul <seanpaul@chromium.org>
> 
> Suggested-by: Daniel Vetter <daniel@ffwll.ch>
> Signed-off-by: Sean Paul <seanpaul@chromium.org>

Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
> ---
>  Documentation/gpu/todo.rst | 15 +++++++++++++++
>  1 file changed, 15 insertions(+)
> 
> diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
> index 38360ede12215..7fc30380eaf6c 100644
> --- a/Documentation/gpu/todo.rst
> +++ b/Documentation/gpu/todo.rst
> @@ -262,6 +262,21 @@ 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.
Bonus points for the link!

	Sam