[PATCH xserver] present: in get_ust_msc hook of wnmd provide CRTC as argument

[Roman Gilg]

For backwards compatibility a driver supporting window flip mode still must
calculate msc values per CRTC.

It is important that the driver returns the msc for the CRTC that Present
requests the msc for or return an error if this is not possible.

This way Present can calculate the offset correctly in
present_wnmd_window_to_crtc_msc.

Signed-off-by: Roman Gilg <subdiff at gmail.com>
---
 hw/xwayland/xwayland-present.c | 10 +++++++++-
 present/present.h              |  2 +-
 present/present_wnmd.c         | 14 +++++++++-----
 3 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/hw/xwayland/xwayland-present.c b/hw/xwayland/xwayland-present.c
index 66bfaae..adc3a68 100644
--- a/hw/xwayland/xwayland-present.c
+++ b/hw/xwayland/xwayland-present.c
@@ -258,11 +258,19 @@ xwl_present_get_crtc(WindowPtr present_window)
 }
 
 static int
-xwl_present_get_ust_msc(WindowPtr present_window, uint64_t *ust, uint64_t *msc)
+xwl_present_get_ust_msc(WindowPtr present_window, RRCrtcPtr crtc, uint64_t *ust, uint64_t *msc)
 {
     struct xwl_window *xwl_window = xwl_window_from_window(present_window);
     if (!xwl_window)
         return BadAlloc;
+
+    if (xwl_window->present_crtc_fake != crtc) {
+        /* the crtc changed between the last call and this one,
+         * falls back to using the saved window msc in Present
+         */
+        return BadMatch;
+    }
+
     *ust = xwl_window->present_ust;
     *msc = xwl_window->present_msc;
 
diff --git a/present/present.h b/present/present.h
index 3d0b972..0a3682c 100644
--- a/present/present.h
+++ b/present/present.h
@@ -41,7 +41,7 @@ typedef RRCrtcPtr (*present_get_crtc_ptr) (WindowPtr window);
 /* Return the current ust/msc for 'crtc'
  */
 typedef int (*present_get_ust_msc_ptr) (RRCrtcPtr crtc, uint64_t *ust, uint64_t *msc);
-typedef int (*present_wnmd_get_ust_msc_ptr) (WindowPtr window, uint64_t *ust, uint64_t *msc);
+typedef int (*present_wnmd_get_ust_msc_ptr) (WindowPtr window, RRCrtcPtr crtc, uint64_t *ust, uint64_t *msc);
 
 /* Queue callback on 'crtc' for time 'msc'. Call present_event_notify with 'event_id'
  * at or after 'msc'. Return false if it didn't happen (which might occur if 'crtc'
diff --git a/present/present_wnmd.c b/present/present_wnmd.c
index 80ffb01..c95bc92 100644
--- a/present/present_wnmd.c
+++ b/present/present_wnmd.c
@@ -61,10 +61,10 @@ present_wnmd_get_crtc(present_screen_priv_ptr screen_priv, WindowPtr window)
 }
 
 static int
-present_wnmd_get_ust_msc(ScreenPtr screen, WindowPtr window, uint64_t *ust, uint64_t *msc)
+present_wnmd_get_ust_msc(ScreenPtr screen, WindowPtr window, RRCrtcPtr crtc, uint64_t *ust, uint64_t *msc)
 {
     present_screen_priv_ptr screen_priv = present_screen_priv(screen);
-    return (*screen_priv->wnmd_info->get_ust_msc)(window, ust, msc);
+    return (*screen_priv->wnmd_info->get_ust_msc)(window, crtc, ust, msc);
 }
 
 /*
@@ -76,7 +76,7 @@ present_wnmd_re_execute(present_vblank_ptr vblank)
 {
     uint64_t ust = 0, crtc_msc = 0;
 
-    (void) present_wnmd_get_ust_msc(vblank->screen, vblank->window, &ust, &crtc_msc);
+    (void) present_wnmd_get_ust_msc(vblank->screen, vblank->window, vblank->crtc, &ust, &crtc_msc);
     present_wnmd_execute(vblank, ust, crtc_msc);
 }
 
@@ -518,6 +518,7 @@ present_wnmd_window_to_crtc_msc(WindowPtr window, RRCrtcPtr crtc, uint64_t windo
     present_window_priv_ptr window_priv = present_get_window_priv(window, TRUE);
 
     if (crtc != window_priv->crtc) {
+        uint64_t old_ust, old_msc;
         if (window_priv->crtc == PresentCrtcNeverSet) {
             window_priv->msc_offset = 0;
         } else {
@@ -525,7 +526,10 @@ present_wnmd_window_to_crtc_msc(WindowPtr window, RRCrtcPtr crtc, uint64_t windo
              * we'll just use whatever previous MSC we'd seen from this CRTC
              */
 
-            window_priv->msc_offset += new_msc - window_priv->msc;
+            if (present_wnmd_get_ust_msc(window->drawable.pScreen, window, window_priv->crtc, &old_ust, &old_msc) != Success)
+                old_msc = window_priv->msc;
+
+            window_priv->msc_offset += new_msc - old_msc;
         }
         window_priv->crtc = crtc;
     }
@@ -565,7 +569,7 @@ present_wnmd_pixmap(WindowPtr window,
 
     target_crtc = present_wnmd_get_crtc(screen_priv, window);
 
-    ret = present_wnmd_get_ust_msc(screen, window, &ust, &crtc_msc);
+    ret = present_wnmd_get_ust_msc(screen, window, target_crtc, &ust, &crtc_msc);
 
     target_msc = present_wnmd_window_to_crtc_msc(window, target_crtc, window_msc, crtc_msc);
 
-- 
2.7.4