From 5a1cb0989274fd745569a60c28c9a5ca729cabf6 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Michel=20D=C3=A4nzer?= <michel.daenzer@amd.com>

Date: Thu, 1 Nov 2018 18:44:24 +0100

Subject: [PATCH xserver 4/7] xwayland: Replace xwl_window::present_window with

 ::present_flipped

There's no need to keep track of the window which last performed a

Present flip. This fixes crashes due to the assertion in

xwl_present_flips_stop failing. Fixes issue #10.

The damage generated by a flip only needs to be ignored once, then

xwl_window::present_flipped can be cleared. This may fix freezing in

the (hypothetical) scenario where Present flips are performed on a

window, followed by other drawing requests using the window as the

destination, but nothing triggering xwl_present_flips_stop. The damage

from the latter drawing requests would continue being ignored.

(cherry picked from commit 6b016d58d23d16eaae9908a92ed90547d1926317)

---

 hw/xwayland/xwayland-present.c | 56 ++++++++--------------------------

 hw/xwayland/xwayland.c         | 17 ++++++++---

 hw/xwayland/xwayland.h         |  4 ++-

 3 files changed, 27 insertions(+), 50 deletions(-)

diff --git a/hw/xwayland/xwayland-present.c b/hw/xwayland/xwayland-present.c

index 4f517d46b..e6dca5ed0 100644

--- a/hw/xwayland/xwayland-present.c

+++ b/hw/xwayland/xwayland-present.c

@@ -90,24 +90,19 @@ xwl_present_has_events(struct xwl_present_window *xwl_present_window)

            !xorg_list_is_empty(&xwl_present_window->release_queue);

 }

-static inline Bool

-xwl_present_is_flipping(WindowPtr window, struct xwl_window *xwl_window)

-{

-    return xwl_window && xwl_window->present_window == window;

-}

-

 static void

 xwl_present_reset_timer(struct xwl_present_window *xwl_present_window)

 {

     if (xwl_present_has_events(xwl_present_window)) {

-        WindowPtr present_window = xwl_present_window->window;

-        Bool is_flipping = xwl_present_is_flipping(present_window,

-                                                   xwl_window_from_window(present_window));

+        CARD32 timeout;

+

+        if (xwl_present_window->frame_callback)

+            timeout = TIMER_LEN_FLIP;

+        else

+            timeout = TIMER_LEN_COPY;

         xwl_present_window->frame_timer = TimerSet(xwl_present_window->frame_timer,

-                                                   0,

-                                                   is_flipping ? TIMER_LEN_FLIP :

-                                                                 TIMER_LEN_COPY,

+                                                   0, timeout,

                                                    &xwl_present_timer_callback,

                                                    xwl_present_window);

     } else {

@@ -118,16 +113,12 @@ xwl_present_reset_timer(struct xwl_present_window *xwl_present_window)

 void

 xwl_present_cleanup(WindowPtr window)

 {

-    struct xwl_window *xwl_window = xwl_window_from_window(window);

     struct xwl_present_window *xwl_present_window = xwl_present_window_priv(window);

     struct xwl_present_event *event, *tmp;

     if (!xwl_present_window)

         return;

-    if (xwl_window && xwl_window->present_window == window)

-        xwl_window->present_window = NULL;

-

     if (xwl_present_window->frame_callback) {

         wl_callback_destroy(xwl_present_window->frame_callback);

         xwl_present_window->frame_callback = NULL;

@@ -361,10 +352,6 @@ xwl_present_queue_vblank(WindowPtr present_window,

     if (!xwl_window)

         return BadMatch;

-    if (xwl_window->present_window &&

-            xwl_window->present_window != present_window)

-        return BadMatch;

-

     event = malloc(sizeof *event);

     if (!event)

         return BadAlloc;

@@ -433,13 +420,6 @@ xwl_present_check_flip2(RRCrtcPtr crtc,

     if (!xwl_window)

         return FALSE;

-    /*

-     * Do not flip if there is already another child window doing flips.

-     */

-    if (xwl_window->present_window &&

-            xwl_window->present_window != present_window)

-        return FALSE;

-

     /*

      * We currently only allow flips of windows, that have the same

      * dimensions as their xwl_window parent window. For the case of

@@ -476,8 +456,6 @@ xwl_present_flip(WindowPtr present_window,

     if (!event)

         return FALSE;

-    xwl_window->present_window = present_window;

-

     buffer = xwl_glamor_pixmap_get_wl_buffer(pixmap, &buffer_created);

     event->event_id = event_id;

@@ -502,13 +480,6 @@ xwl_present_flip(WindowPtr present_window,

     /* We can flip directly to the main surface (full screen window without clips) */

     wl_surface_attach(xwl_window->surface, buffer, 0, 0);

-    if (!xwl_present_window->frame_timer ||

-            xwl_present_window->frame_timer_firing) {

-        /* Realign timer */

-        xwl_present_window->frame_timer_firing = FALSE;

-        xwl_present_reset_timer(xwl_present_window);

-    }

-

     if (!xwl_present_window->frame_callback) {

         xwl_present_window->frame_callback = wl_surface_frame(xwl_window->surface);

         wl_callback_add_listener(xwl_present_window->frame_callback,

@@ -516,6 +487,10 @@ xwl_present_flip(WindowPtr present_window,

                                  xwl_present_window);

     }

+    /* Realign timer */

+    xwl_present_window->frame_timer_firing = FALSE;

+    xwl_present_reset_timer(xwl_present_window);

+

     wl_surface_damage(xwl_window->surface, 0, 0,

                       damage_box->x2 - damage_box->x1,

                       damage_box->y2 - damage_box->y1);

@@ -531,22 +506,15 @@ xwl_present_flip(WindowPtr present_window,

     }

     wl_display_flush(xwl_window->xwl_screen->display);

+    xwl_window->present_flipped = TRUE;

     return TRUE;

 }

 static void

 xwl_present_flips_stop(WindowPtr window)

 {

-    struct xwl_window *xwl_window = xwl_window_from_window(window);

     struct xwl_present_window   *xwl_present_window = xwl_present_window_priv(window);

-    if (!xwl_window)

-        return;

-

-    assert(xwl_window->present_window == window);

-

-    xwl_window->present_window = NULL;

-

     /* Change back to the fast refresh rate */

     xwl_present_reset_timer(xwl_present_window);

 }

diff --git a/hw/xwayland/xwayland.c b/hw/xwayland/xwayland.c

index 96b4db18c..988b8e17d 100644

--- a/hw/xwayland/xwayland.c

+++ b/hw/xwayland/xwayland.c

@@ -370,6 +370,18 @@ damage_report(DamagePtr pDamage, RegionPtr pRegion, void *data)

     struct xwl_window *xwl_window = data;

     struct xwl_screen *xwl_screen = xwl_window->xwl_screen;

+#ifdef GLAMOR_HAS_GBM

+    if (xwl_window->present_flipped) {

+        /* This damage is from a Present flip, which already committed a new

+         * buffer for the surface, so we don't need to do anything in response

+         */

+        RegionEmpty(DamageRegion(pDamage));

+        xorg_list_del(&xwl_window->link_damage);

+        xwl_window->present_flipped = FALSE;

+        return;

+    }

+#endif

+

     xorg_list_add(&xwl_window->link_damage, &xwl_screen->damage_window_list);

 }

@@ -721,11 +733,6 @@ xwl_screen_post_damage(struct xwl_screen *xwl_screen)

     xorg_list_for_each_entry_safe(xwl_window, next_xwl_window,

                                   &xwl_screen->damage_window_list, link_damage) {

-#ifdef GLAMOR_HAS_GBM

-        /* Present on the main surface. So don't commit here as well. */

-        if (xwl_window->present_window)

-            continue;

-#endif

         /* If we're waiting on a frame callback from the server,

          * don't attach a new buffer. */

         if (xwl_window->frame_callback)

diff --git a/hw/xwayland/xwayland.h b/hw/xwayland/xwayland.h

index 3f4a601fe..a79f836ad 100644

--- a/hw/xwayland/xwayland.h

+++ b/hw/xwayland/xwayland.h

@@ -182,7 +182,9 @@ struct xwl_window {

     struct xorg_list link_damage;

     struct wl_callback *frame_callback;

     Bool allow_commits;

-    WindowPtr present_window;

+#ifdef GLAMOR_HAS_GBM

+    Bool present_flipped;

+#endif

 };

 #ifdef GLAMOR_HAS_GBM

-- 

2.19.2