compositor-drm: Clean up page_flip_pending path
page_flip_pending is only be set when do a pageflip to a newly-rendered
buffer; if the flag is not set, we have landed in the start_repaint_loop
path where the vblank query fails, and thus we must pageflip to the same
buffer.
This test was not sufficient for what it was supposed to guard:
releasing framebuffers back. When using client-supplied framebuffers, it
is possible to reuse the same buffer multiple times, and we would send a
framebuffer-release event too early.
However, since we have a properly reference-counted drm_fb now, we can
just drop this test, and rely on the reference counting to prevent
too-early release of client framebuffers.
page_flip_pending now becomes exactly what the name suggests: a flag
which indicates whether or not we are expecting a pageflip event. Add
asserts here to verify that we never receive a pageflip event we weren't
expecting.
Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c
index 8878237..f9b0737 100644
--- a/libweston/compositor-drm.c
+++ b/libweston/compositor-drm.c
@@ -883,6 +883,7 @@
output->fb_current = output->fb_pending;
output->fb_pending = NULL;
+ assert(!output->page_flip_pending);
output->page_flip_pending = 1;
if (output->pageflip_timer)
@@ -1008,6 +1009,9 @@
*/
fb_id = output->fb_current->fb_id;
+ assert(!output->page_flip_pending);
+ assert(!output->fb_last);
+
if (drmModePageFlip(backend->drm.fd, output->crtc_id, fb_id,
DRM_MODE_PAGE_FLIP_EVENT, output) < 0) {
weston_log("queueing pageflip failed: %m\n");
@@ -1018,6 +1022,9 @@
wl_event_source_timer_update(output->pageflip_timer,
backend->pageflip_timeout);
+ output->fb_last = drm_fb_ref(output->fb_current);
+ output->page_flip_pending = 1;
+
return;
finish_frame:
@@ -1081,16 +1088,12 @@
drm_output_update_msc(output, frame);
- /* We don't set page_flip_pending on start_repaint_loop, in that case
- * we just want to page flip to the current buffer to get an accurate
- * timestamp */
- if (output->page_flip_pending) {
- drm_fb_unref(output->fb_last);
- output->fb_last = NULL;
- }
-
+ assert(output->page_flip_pending);
output->page_flip_pending = 0;
+ drm_fb_unref(output->fb_last);
+ output->fb_last = NULL;
+
if (output->destroy_pending)
drm_output_destroy(&output->base);
else if (output->disable_pending)