From 7b12a45b2dc6993e3f31642df2cc9b528294da40 Mon Sep 17 00:00:00 2001

From: David Herrmann <dh.herrmann@gmail.com>

Date: Sat, 20 Sep 2014 11:12:44 +0200

Subject: [PATCH] terminal: grdev: schedule virtual frame events if hw doesn't

 support it

Whenever we cannot use hardware frame events, we now schedule a virtual

frame event to make sure applications don't have to do this. Usually,

applications render only on data changes, but we can further reduce

render-time by also limiting rendering to vsyncs.

---

 src/libsystemd-terminal/grdev-drm.c      | 17 +++++++-

 src/libsystemd-terminal/grdev-internal.h |  3 ++

 src/libsystemd-terminal/grdev.c          | 69 +++++++++++++++++++++++++++-----

 3 files changed, 79 insertions(+), 10 deletions(-)

diff --git a/src/libsystemd-terminal/grdev-drm.c b/src/libsystemd-terminal/grdev-drm.c

index 00aac292d2..3936a029fa 100644

--- a/src/libsystemd-terminal/grdev-drm.c

+++ b/src/libsystemd-terminal/grdev-drm.c

@@ -346,6 +346,8 @@ static bool grdrm_modes_compatible(const struct drm_mode_modeinfo *a, const stru

                 return false;

         if (a->vdisplay != b->vdisplay)

                 return false;

+        if (a->vrefresh != b->vrefresh)

+                return false;

         return true;

 }

@@ -1038,7 +1040,8 @@ static void grdrm_crtc_expose(grdrm_crtc *crtc) {

         pipe = crtc->pipe;

         if (pipe) {

                 if (pipe->base.width != crtc->set.mode.hdisplay ||

-                    pipe->base.height != crtc->set.mode.vdisplay) {

+                    pipe->base.height != crtc->set.mode.vdisplay ||

+                    pipe->base.vrefresh != crtc->set.mode.vrefresh) {

                         grdev_pipe_free(&pipe->base);

                         crtc->pipe = NULL;

                         pipe = NULL;

@@ -1127,6 +1130,12 @@ static void grdrm_crtc_commit_deep(grdrm_crtc *crtc, grdev_fb **slot) {

         pipe->base.flipping = false;

         pipe->base.flip = false;

+        /* We cannot schedule dummy page-flips on pipes, hence, the

+         * application would have to schedule their own frame-timers.

+         * To avoid duplicating that everywhere, we schedule our own

+         * timer and raise a fake FRAME event when it fires. */

+        grdev_pipe_schedule(&pipe->base, 1);

+

         if (!pipe->base.back) {

                 for (i = 0; i < pipe->base.max_fbs; ++i) {

                         if (!pipe->base.fbs[i])

@@ -1189,6 +1198,11 @@ static int grdrm_crtc_commit_flip(grdrm_crtc *crtc, grdev_fb **slot) {

         fb->flipid = cnt;

         *slot = NULL;

+        /* Raise fake FRAME event if it takes longer than 2

+         * frames to receive the pageflip event. We assume the

+         * queue ran over or some other error happened. */

+        grdev_pipe_schedule(&pipe->base, 2);

+

         if (!pipe->base.back) {

                 for (i = 0; i < pipe->base.max_fbs; ++i) {

                         if (!pipe->base.fbs[i])

@@ -1501,6 +1515,7 @@ static int grdrm_pipe_new(grdrm_pipe **out, grdrm_crtc *crtc, struct drm_mode_mo

         pipe->crtc = crtc;

         pipe->base.width = mode->hdisplay;

         pipe->base.height = mode->vdisplay;

+        pipe->base.vrefresh = mode->vrefresh ? : 25;

         grdrm_pipe_name(name, crtc);

         r = grdev_pipe_add(&pipe->base, name, n_fbs);

diff --git a/src/libsystemd-terminal/grdev-internal.h b/src/libsystemd-terminal/grdev-internal.h

index 96830a714c..f5915b16e8 100644

--- a/src/libsystemd-terminal/grdev-internal.h

+++ b/src/libsystemd-terminal/grdev-internal.h

@@ -142,9 +142,11 @@ struct grdev_pipe {

         grdev_tile *tile;

         grdev_display_cache *cache;

+        sd_event_source *vsync_src;

         uint32_t width;

         uint32_t height;

+        uint32_t vrefresh;

         size_t max_fbs;

         grdev_fb *front;

@@ -171,6 +173,7 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(grdev_pipe*, grdev_pipe_free);

 void grdev_pipe_ready(grdev_pipe *pipe, bool running);

 void grdev_pipe_frame(grdev_pipe *pipe);

+void grdev_pipe_schedule(grdev_pipe *pipe, uint64_t frames);

 /*

  * Cards

diff --git a/src/libsystemd-terminal/grdev.c b/src/libsystemd-terminal/grdev.c

index 397da1b205..43d0c7c9bf 100644

--- a/src/libsystemd-terminal/grdev.c

+++ b/src/libsystemd-terminal/grdev.c

@@ -574,6 +574,13 @@ grdev_pipe *grdev_find_pipe(grdev_card *card, const char *name) {

         return hashmap_get(card->pipe_map, name);

 }

+static int pipe_vsync_fn(sd_event_source *src, uint64_t usec, void *userdata) {

+        grdev_pipe *pipe = userdata;

+

+        grdev_pipe_frame(pipe);

+        return 0;

+}

+

 int grdev_pipe_add(grdev_pipe *pipe, const char *name, size_t n_fbs) {

         int r;

@@ -585,6 +592,7 @@ int grdev_pipe_add(grdev_pipe *pipe, const char *name, size_t n_fbs) {

         assert_return(!pipe->cache, -EINVAL);

         assert_return(pipe->width > 0, -EINVAL);

         assert_return(pipe->height > 0, -EINVAL);

+        assert_return(pipe->vrefresh > 0, -EINVAL);

         assert_return(!pipe->enabled, -EINVAL);

         assert_return(!pipe->running, -EINVAL);

         assert_return(name, -EINVAL);

@@ -605,6 +613,20 @@ int grdev_pipe_add(grdev_pipe *pipe, const char *name, size_t n_fbs) {

         if (r < 0)

                 return r;

+        r = sd_event_add_time(pipe->card->session->context->event,

+                              &pipe->vsync_src,

+                              CLOCK_MONOTONIC,

+                              0,

+                              10 * USEC_PER_MSEC,

+                              pipe_vsync_fn,

+                              pipe);

+        if (r < 0)

+                return r;

+

+        r = sd_event_source_set_enabled(pipe->vsync_src, SD_EVENT_OFF);

+        if (r < 0)

+                return r;

+

         r = hashmap_put(pipe->card->pipe_map, pipe->name, pipe);

         if (r < 0)

                 return r;

@@ -633,6 +655,7 @@ grdev_pipe *grdev_pipe_free(grdev_pipe *pipe) {

         tmp = *pipe;

         pipe->vtable->free(pipe);

+        sd_event_source_unref(tmp.vsync_src);

         grdev_tile_free(tmp.tile);

         card_modified(tmp.card);

         free(tmp.fbs);

@@ -676,17 +699,15 @@ void grdev_pipe_ready(grdev_pipe *pipe, bool running) {

         pipe->running = running;

         /* runtime events for unused pipes are not interesting */

-        if (pipe->cache) {

+        if (pipe->cache && pipe->enabled) {

                 grdev_display *display = pipe->tile->display;

                 assert(display);

-                if (running) {

-                        if (pipe->enabled)

-                                session_frame(display->session, display);

-                } else {

+                if (running)

+                        session_frame(display->session, display);

+                else

                         pipe->cache->incomplete = true;

-                }

         }

 }

@@ -696,14 +717,44 @@ void grdev_pipe_frame(grdev_pipe *pipe) {

         assert(pipe);

         /* if pipe is unused, ignore any frame events */

-        if (!pipe->cache)

+        if (!pipe->cache || !pipe->enabled)

                 return;

         display = pipe->tile->display;

         assert(display);

-        if (pipe->enabled)

-                session_frame(display->session, display);

+        grdev_pipe_schedule(pipe, 0);

+        session_frame(display->session, display);

+}

+

+void grdev_pipe_schedule(grdev_pipe *pipe, uint64_t frames) {

+        int r;

+        uint64_t ts;

+

+        if (!frames) {

+                sd_event_source_set_enabled(pipe->vsync_src, SD_EVENT_OFF);

+                return;

+        }

+

+        r = sd_event_now(pipe->card->session->context->event, CLOCK_MONOTONIC, &ts);

+        if (r < 0)

+                goto error;

+

+        ts += frames * USEC_PER_MSEC * 1000ULL / pipe->vrefresh;

+

+        r = sd_event_source_set_time(pipe->vsync_src, ts);

+        if (r < 0)

+                goto error;

+

+        r = sd_event_source_set_enabled(pipe->vsync_src, SD_EVENT_ONESHOT);

+        if (r < 0)

+                goto error;

+

+        return;

+

+error:

+        log_debug("grdev: %s/%s/%s: cannot schedule vsync timer: %s",

+                  pipe->card->session->name, pipe->card->name, pipe->name, strerror(-r));

 }

 /*