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 <[email protected]> Differential Revision: https://phabricator.freedesktop.org/D1417 Signed-off-by: Daniel Stone <[email protected]> --- libweston/compositor-drm.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c index 21415775..88975007 100644 --- a/libweston/compositor-drm.c +++ b/libweston/compositor-drm.c @@ -883,6 +883,7 @@ drm_output_repaint(struct weston_output *output_base, 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 @@ drm_output_start_repaint_loop(struct weston_output *output_base) */ 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 @@ drm_output_start_repaint_loop(struct weston_output *output_base) 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 @@ page_flip_handler(int fd, unsigned int frame, 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) -- 2.12.2 _______________________________________________ wayland-devel mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/wayland-devel
