compositor-drm: Make scanout view preparation more stringent

Don't import buffers which span multiple outputs, short-cut any attempt
to import SHM buffers, and ignore buffers with a global alpha set.

I'm not convinced all of these conditions entirely make sense, but this
at least makes them equally nonsensical.

Differential Revision: https://phabricator.freedesktop.org/D1414

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Derek Foreman <derekf@osg.samsung.com>

diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c
index b70339c..7f78699 100644 (file)
--- a/libweston/compositor-drm.c
+++ b/libweston/compositor-drm.c
@@ -499,6 +499,13 @@ drm_output_release_fb(struct drm_output *output, struct drm_fb *fb)
        }
 }
 
+static int
+drm_view_transform_supported(struct weston_view *ev)
+{
+       return !ev->transform.enabled ||
+               (ev->transform.matrix.type < WESTON_MATRIX_TRANSFORM_ROTATE);
+}
+
 static uint32_t
 drm_output_check_scanout_format(struct drm_output *output,
                                struct weston_surface *es, struct gbm_bo *bo)
@@ -539,27 +546,40 @@ drm_output_prepare_scanout_view(struct drm_output *output,
        struct gbm_bo *bo;
        uint32_t format;
 
+       /* Don't import buffers which span multiple outputs. */
+       if (ev->output_mask != (1u << output->base.id))
+               return NULL;
+
        /* We use GBM to import buffers. */
        if (b->gbm == NULL)
                return NULL;
 
        if (buffer == NULL)
                return NULL;
+       if (wl_shm_buffer_get(buffer->resource))
+               return NULL;
 
        /* Make sure our view is exactly compatible with the output. */
        if (ev->geometry.x != output->base.x ||
            ev->geometry.y != output->base.y)
                return NULL;
+       if (buffer->width != output->base.current_mode->width ||
+           buffer->height != output->base.current_mode->height)
+               return NULL;
+
        if (ev->transform.enabled)
                return NULL;
        if (ev->geometry.scissor_enabled)
                return NULL;
-
-       if (buffer->width != output->base.current_mode->width ||
-           buffer->height != output->base.current_mode->height)
-               return NULL;
        if (viewport->buffer.transform != output->base.transform)
                return NULL;
+       if (viewport->buffer.scale != output->base.current_scale)
+               return NULL;
+       if (!drm_view_transform_supported(ev))
+               return NULL;
+
+       if (ev->alpha != 1.0f)
+               return NULL;
 
        bo = gbm_bo_import(b->gbm, GBM_BO_IMPORT_WL_BUFFER,
                           buffer->resource, GBM_BO_USE_SCANOUT);
@@ -973,13 +993,6 @@ drm_output_check_sprite_format(struct drm_sprite *s,
        return 0;
 }
 
-static int
-drm_view_transform_supported(struct weston_view *ev)
-{
-       return !ev->transform.enabled ||
-               (ev->transform.matrix.type < WESTON_MATRIX_TRANSFORM_ROTATE);
-}
-
 static struct weston_plane *
 drm_output_prepare_overlay_view(struct drm_output *output,
                                struct weston_view *ev)