On 02/12/2014 20:53, Mario Kleiner wrote :
glXSwapBuffersMscOML() with target_msc=divisor=remainder=0 gets translated into target_msc=divisor=0 but remainder=1 by the mesa api. This is done for server DRI2 where there needs to be a way to tell the server-side DRI2ScheduleSwap implementation if a call to glXSwapBuffers() or glXSwapBuffersMscOML(dpy,window,0,0,0) was done. remainder = 1 was (ab)used as a flag to tell the server to select proper semantic. The DRI3/Present backend ignored this signalling, treated any target_msc=0 as glXSwapBuffers() request, and called xcb_present_pixmap with invalid divisor=0, remainder=1 combo. The present extension responded kindly to this with a BadValue error and dropped the request, but mesa's DRI3/Present backend doesn't check for error codes. From there on stuff went downhill quickly for the calling OpenGL client...This patch fixes the problem. Cc: "10.3 10.4" <mesa-sta...@lists.freedesktop.org> Signed-off-by: Mario Kleiner <mario.kleiner...@gmail.com> --- src/glx/dri3_glx.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/src/glx/dri3_glx.c b/src/glx/dri3_glx.c index c53be1b..efff907 100644 --- a/src/glx/dri3_glx.c +++ b/src/glx/dri3_glx.c @@ -1552,11 +1552,21 @@ dri3_swap_buffers(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor, dri3_fence_reset(c, back);/* Compute when we want the frame shown by taking the last known successful- * MSC and adding in a swap interval for each outstanding swap request + * MSC and adding in a swap interval for each outstanding swap request. + * target_msc=divisor=remainder=0 means "Use glXSwapBuffers() semantic" */ ++priv->send_sbc; - if (target_msc == 0) + if (target_msc == 0 && divisor == 0 && remainder == 0) target_msc = priv->msc + priv->swap_interval * (priv->send_sbc - priv->recv_sbc); + else if (divisor == 0 && remainder > 0) { + /* Special case signalling: This means "glXSwapBuffersMscOML() called with + * target_msc=divisor=remainder=0. Needed to distinguish from glXSwapBuffers + * case above. Reset remainder to zero, so PresentPixmap won't bail on us. + * GLX_OML_sync_control says for divisor == 0 any remainder >= 0 is fine, + * whereas Present extension wants remainder == 0 for divisor == 0. + */ + remainder = 0; + }if (priv->swap_interval == 0)options |= XCB_PRESENT_OPTION_ASYNC;
It seems a bit heavy, but I don't find a better way to handle the case you describe.
Reviewed-by: Axel Davy <axel.d...@ens.fr> _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
