[PATCH 4/5] drm/atomic-helper: Reject legacy flips on a disabled pipe

[Ilia Mirkin]

On Tue, Dec 8, 2015 at 3:49 AM, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> We want this for consistency with existing page_flip semantics.
>
> Since this spurred quite a discussion on IRC also document why we
> reject even generation when the pipe is off: It's not that it's hard

event generation?

> to implement, but userspace has a track recording proofing that it's

has a track record which proves that it's

> way too easy to accidentally abuse and cause havoc. We want to make
> sure userspace doesn't get away with that.
>
> v2: Somehow thought we do reject events already, but that code only
> existed in my imagination ... Also suggestions from Thierry.
>
> Cc: Daniel Stone <daniels at collabora.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Thierry Reding <thierry.reding at gmail.com>
> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
>  drivers/gpu/drm/drm_atomic.c        | 16 ++++++++++++++++
>  drivers/gpu/drm/drm_atomic_helper.c |  9 +++++++++
>  include/drm/drm_crtc.h              |  3 ++-
>  3 files changed, 27 insertions(+), 1 deletion(-)