Den 09.05.2016 16:46, skrev Daniel Vetter:
On Thu, May 05, 2016 at 03:24:33PM +0200, Noralf Trønnes wrote:
Provides helper functions for drivers that have a simple display
pipeline. Plane, crtc and encoder are collapsed into one entity.
Signed-off-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
+static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
+ struct drm_plane_state *pstate)
+{
+ struct drm_simple_display_pipe *pipe;
+ struct drm_crtc_state *cstate;
+
+ pipe = container_of(plane, struct drm_simple_display_pipe, plane);
+ if (!pipe->funcs || !pipe->funcs->check)
+ return 0;
+
+ cstate = drm_atomic_get_existing_crtc_state(pstate->state,
+ &pipe->crtc);
+
+ return pipe->funcs->check(pipe, pstate, cstate);
+}
Ok one thing I've missed here is that for most drivers this is way too
simple a check function, which means we'll end up with tons of duplicated
code. Things which the drm core allows, but simple pipelines all don't
really cope with:
- plane scaling
- disabling the plane without the crtc (i.e. scan out black)
- plane not sized to fill the entire hactive/vactive
There's a helper to do most of these checks for you -
drm_plane_helper_check_update. I think it'd be good to place a call for
that in here, before we call down into the driver's ->check callback. But
ofc before we return 0; we want these checks always done. And catch all
these things so that drivers never fall over this pitfall.
Does this resemble what you're after? I'm just guessing here.
static int drm_simple_kms_plane_atomic_check(struct drm_plane *plane,
struct drm_plane_state *pstate)
{
struct drm_rect src = {
.x1 = pstate->src_x,
.y1 = pstate->src_y,
.x2 = pstate->src_x + pstate->src_w,
.y2 = pstate->src_y + pstate->src_h,
};
struct drm_rect dest = {
.x1 = pstate->crtc_x,
.y1 = pstate->crtc_y,
.x2 = pstate->crtc_x + pstate->crtc_w,
.y2 = pstate->crtc_y + pstate->crtc_h,
};
struct drm_rect clip = { 0 };
struct drm_simple_display_pipe *pipe;
struct drm_crtc_state *cstate;
bool visible;
int ret;
pipe = container_of(plane, struct drm_simple_display_pipe, plane);
clip.x2 = pipe->crtc.mode.hdisplay;
clip.y2 = pipe->crtc.mode.vdisplay;
ret = drm_plane_helper_check_update(plane, &pipe->crtc, plane->fb,
&src, &dest, &clip,
DRM_PLANE_HELPER_NO_SCALING,
DRM_PLANE_HELPER_NO_SCALING,
false, false, &visible);
if (ret)
return ret;
/* How to handle !visible, is it even possible? */
if (!pipe->funcs || !pipe->funcs->check)
return 0;
cstate = drm_atomic_get_existing_crtc_state(pstate->state,
&pipe->crtc);
return pipe->funcs->check(pipe, pstate, cstate);
}
Noralf.
Noticed while discussing tilcdc atomic patches, since tilcdc could
probably use drm_simple_display_pipe too.
-Daniel
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel
