diff --git a/backend/drm/drm.c b/backend/drm/drm.c index 18e9a64e..0f118c17 100644 --- a/backend/drm/drm.c +++ b/backend/drm/drm.c @@ -106,6 +106,10 @@ bool check_drm_features(struct wlr_drm_backend *drm) { drm->iface = &atomic_iface; } + if (drm->iface == &legacy_iface) { + drm->supports_tearing_page_flips = drmGetCap(drm->fd, DRM_CAP_ASYNC_PAGE_FLIP, &cap) == 0 && cap == 1; + } + int ret = drmGetCap(drm->fd, DRM_CAP_TIMESTAMP_MONOTONIC, &cap); drm->clock = (ret == 0 && cap == 1) ? CLOCK_MONOTONIC : CLOCK_REALTIME; @@ -650,6 +654,11 @@ static bool drm_connector_test(struct wlr_output *output, if (!drm_connector_state_update_primary_fb(conn, &pending)) { goto out; } + + if (pending.base->tearing_page_flip && !conn->backend->supports_tearing_page_flips) { + wlr_log(WLR_ERROR, "Attempted to submit a tearing page flip to an unsupported backend!"); + goto out; + } } if (state->committed & WLR_OUTPUT_STATE_LAYERS) { if (!drm_connector_set_pending_layer_fbs(conn, pending.base)) { @@ -725,7 +734,7 @@ bool drm_connector_commit_state(struct wlr_drm_connector *conn, // page-flip, either a blocking modeset. When performing a blocking modeset // we'll wait for all queued page-flips to complete, so we don't need this // safeguard. - if (conn->pending_page_flip_crtc && !pending.modeset) { + if (conn->pending_page_flip_crtc && !pending.modeset && !pending.base->tearing_page_flip) { wlr_drm_conn_log(conn, WLR_ERROR, "Failed to page-flip output: " "a page-flip is already pending"); goto out; @@ -748,6 +757,9 @@ bool drm_connector_commit_state(struct wlr_drm_connector *conn, } uint32_t flags = pending.active ? DRM_MODE_PAGE_FLIP_EVENT : 0; + if (pending.base->tearing_page_flip) { + flags |= DRM_MODE_PAGE_FLIP_ASYNC; + } ok = drm_crtc_commit(conn, &pending, flags, false); if (!ok) { diff --git a/backend/drm/legacy.c b/backend/drm/legacy.c index a8f618cf..ee64f78c 100644 --- a/backend/drm/legacy.c +++ b/backend/drm/legacy.c @@ -175,8 +175,13 @@ static bool legacy_crtc_commit(struct wlr_drm_connector *conn, } if (flags & DRM_MODE_PAGE_FLIP_EVENT) { + uint32_t page_flags = DRM_MODE_PAGE_FLIP_EVENT; + if (flags & DRM_MODE_PAGE_FLIP_ASYNC) { + page_flags |= DRM_MODE_PAGE_FLIP_ASYNC; + } + if (drmModePageFlip(drm->fd, crtc->id, fb_id, - DRM_MODE_PAGE_FLIP_EVENT, drm)) { + page_flags, drm)) { wlr_drm_conn_log_errno(conn, WLR_ERROR, "drmModePageFlip failed"); return false; } diff --git a/include/backend/drm/drm.h b/include/backend/drm/drm.h index 4b92c5eb..69416925 100644 --- a/include/backend/drm/drm.h +++ b/include/backend/drm/drm.h @@ -114,6 +114,8 @@ struct wlr_drm_backend { uint64_t cursor_width, cursor_height; struct wlr_drm_format_set mgpu_formats; + + bool supports_tearing_page_flips; }; struct wlr_drm_mode { diff --git a/include/wlr/types/wlr_output.h b/include/wlr/types/wlr_output.h index 30331fba..de7ea332 100644 --- a/include/wlr/types/wlr_output.h +++ b/include/wlr/types/wlr_output.h @@ -89,6 +89,12 @@ struct wlr_output_state { enum wl_output_subpixel subpixel; struct wlr_buffer *buffer; + /* Request a tearing page-flip. When enabled, this may cause the output to + * display a part of the previous buffer and a part of the current buffer at + * the same time. The backend may reject the commit if a tearing page-flip + * cannot be performed, in which case the caller should fall back to a + * regular page-flip at the next wlr_output.frame event. */ + bool tearing_page_flip; enum wlr_output_state_mode_type mode_type; struct wlr_output_mode *mode; diff --git a/types/output/output.c b/types/output/output.c index b4301802..278ecb9e 100644 --- a/types/output/output.c +++ b/types/output/output.c @@ -665,6 +665,9 @@ static bool output_basic_test(struct wlr_output *output, wlr_log(WLR_DEBUG, "Primary buffer size mismatch"); return false; } + } else if (state->tearing_page_flip) { + wlr_log(WLR_ERROR, "Trying to commit a tearing page flip without a buffer?"); + return false; } if (state->committed & WLR_OUTPUT_STATE_RENDER_FORMAT) {