xf86-video-intel: src/sna/sna_display.c

[Chris Wilson]

 src/sna/sna_display.c |   47 +++++++++++++++++++++++++++++++++--------------
 1 file changed, 33 insertions(+), 14 deletions(-)

New commits:
commit 19a95be5e94841d908633425582e09c7718e3805
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date:   Wed Dec 31 11:53:45 2014 +0000

    sna: Don't record old vblank events
    
    When we read vblank events back from the fd, we have to be wary in case
    they are older than the most recent vblank query. If they are stale, we
    do not want to record them as being the last-known vblank event.
    
    Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>

diff --git a/src/sna/sna_display.c b/src/sna/sna_display.c
index 4b218b7..c2c7406 100644
--- a/src/sna/sna_display.c
+++ b/src/sna/sna_display.c
@@ -299,34 +299,48 @@ bool sna_crtc_is_transformed(xf86CrtcPtr crtc)
 	return to_sna_crtc(crtc)->transform;
 }
 
-static inline uint64_t msc64(struct sna_crtc *sna_crtc, uint32_t seq)
+static inline bool msc64(struct sna_crtc *sna_crtc, uint32_t seq, uint64_t *msc)
 {
+	bool record = true;
 	if (seq < sna_crtc->last_seq) {
 		if (sna_crtc->last_seq - seq > 0x40000000) {
 			sna_crtc->wrap_seq++;
 			DBG(("%s: pipe=%d wrapped; was %u, now %u, wraps=%u\n",
 			     __FUNCTION__, sna_crtc->pipe,
 			     sna_crtc->last_seq, seq, sna_crtc->wrap_seq));
-		} else  {
-			ERR(("%s: pipe=%d msc went backwards; was %u, now %u\n",
+		} else {
+			DBG(("%s: pipe=%d msc went backwards; was %u, now %u; ignoring for last_swap\n",
 			     __FUNCTION__, sna_crtc->pipe, sna_crtc->last_seq, seq));
-			seq = sna_crtc->last_seq;
+
+			record = false;
 		}
 	}
-	sna_crtc->last_seq = seq;
-	return (uint64_t)sna_crtc->wrap_seq << 32 | seq;
+	*msc = (uint64_t)sna_crtc->wrap_seq << 32 | seq;
+	return record;
 }
 
 uint64_t sna_crtc_record_swap(xf86CrtcPtr crtc,
 			      int tv_sec, int tv_usec, unsigned seq)
 {
 	struct sna_crtc *sna_crtc = to_sna_crtc(crtc);
+	uint64_t msc;
+
 	assert(sna_crtc);
-	DBG(("%s: recording last swap on pipe=%d, frame %d, time %d.%06d\n",
-	     __FUNCTION__, sna_crtc->pipe, seq, tv_sec, tv_usec));
-	sna_crtc->swap.tv_sec = tv_sec;
-	sna_crtc->swap.tv_usec = tv_usec;
-	return sna_crtc->swap.msc = msc64(sna_crtc, seq);
+
+	if (msc64(sna_crtc, seq, &msc)) {
+		DBG(("%s: recording last swap on pipe=%d, frame %d [%08llx], time %d.%06d\n",
+		     __FUNCTION__, sna_crtc->pipe, seq, (long long)msc,
+		     tv_sec, tv_usec));
+		sna_crtc->swap.tv_sec = tv_sec;
+		sna_crtc->swap.tv_usec = tv_usec;
+		sna_crtc->swap.msc = msc;
+	} else {
+		DBG(("%s: swap event on pipe=%d, frame %d [%08llx], time %d.%06d\n",
+		     __FUNCTION__, sna_crtc->pipe, seq, (long long)msc,
+		     tv_sec, tv_usec));
+	}
+
+	return msc;
 }
 
 const struct ust_msc *sna_crtc_last_swap(xf86CrtcPtr crtc)
@@ -7495,13 +7509,18 @@ again:
 			{
 				struct drm_event_vblank *vbl = (struct drm_event_vblank *)e;
 				struct sna_crtc *crtc = (void *)(uintptr_t)vbl->user_data;
+				uint64_t msc;
 
 				/* Beware Zaphod! */
 				sna = to_sna(crtc->base->scrn);
 
-				crtc->swap.tv_sec = vbl->tv_sec;
-				crtc->swap.tv_usec = vbl->tv_usec;
-				crtc->swap.msc = msc64(crtc, vbl->sequence);
+				if (msc64(crtc, vbl->sequence, &msc)) {
+					DBG(("%s: recording last swap on pipe=%d, frame %d [%08llx], time %d.%06d\n",
+					     __FUNCTION__, crtc->pipe, vbl->sequence, (long long)msc, vbl->tv_sec, vbl->tv_usec));
+					crtc->swap.tv_sec = vbl->tv_sec;
+					crtc->swap.tv_usec = vbl->tv_usec;
+					crtc->swap.msc = msc;
+				}
 				crtc->flip_pending = false;
 
 				assert(crtc->flip_bo);