According to the opengl glx_sync_control spec, the Unadjusted System Time (or UST) is a 64-bit monotonically increasing counter that is available throughout the system: http://www.opengl.org/registry/specs/OML/glx_sync_control.txt Therefore, sending 0, even in this corner case, is out of spec. Instead, just return FALSE indicating that the operation could not be completed. Signed-off-by: Daniel Kurtz <djkurtz at chromium.org> --- src/intel_dri.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/src/intel_dri.c b/src/intel_dri.c index f351203..179bfb7 100644 --- a/src/intel_dri.c +++ b/src/intel_dri.c @@ -1339,12 +1339,9 @@ I830DRI2GetMSC(DrawablePtr draw, CARD64 *ust, CARD64 *msc) drmVBlank vbl; int ret, pipe = I830DRI2DrawablePipe(draw); - /* Drawable not displayed, make up a value */ - if (pipe == -1) { - *ust = 0; - *msc = 0; - return TRUE; - } + /* Drawable not displayed, return FALSE */ + if (pipe == -1) + return FALSE; vbl.request.type = DRM_VBLANK_RELATIVE | pipe_select(pipe); vbl.request.sequence = 0; -- 1.8.1.3
