From 455d3036fab2c5da7e589644f12435fb104a69fc Mon Sep 17 00:00:00 2001 From: Mario Kleiner Date: Fri, 5 Dec 2014 08:42:31 +0100 Subject: [PATCH] glx/dri3: Request non-vsynced Present for swapinterval zero. (v3) Restores proper immediate tearing swap behaviour for OpenGL bufferswap under DRI3/Present. Cc: "10.3 10.4" v2: Add Frank Binns signed off by for his original earlier patch from April 2014, which is identical to this one, and Chris Wilsons reviewed tag from May 2014 for that patch, ergo also for this one. v3: Incorporate comment about triple buffering as suggested by Axel Davy, and reference to relevant spec provided by Eric Anholt. Signed-off-by: Frank Binns Signed-off-by: Mario Kleiner Reviewed-by: Chris Wilson Reviewed-by: Axel Davy Reviewed-by: Eric Anholt --- src/glx/dri3_glx.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/src/glx/dri3_glx.c b/src/glx/dri3_glx.c index b89cb463654..3f5e64c2a1e 100644 --- a/src/glx/dri3_glx.c +++ b/src/glx/dri3_glx.c @@ -1526,6 +1526,7 @@ dri3_swap_buffers(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor, xcb_connection_t *c = XGetXCBConnection(dpy); struct dri3_buffer *back; int64_t ret = 0; + uint32_t options = XCB_PRESENT_OPTION_NONE; unsigned flags = __DRI2_FLUSH_DRAWABLE; if (flush) @@ -1565,6 +1566,17 @@ dri3_swap_buffers(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor, if (target_msc == 0) target_msc = priv->msc + priv->swap_interval * (priv->send_sbc - priv->recv_sbc); + /* From the GLX_EXT_swap_control spec: + * + * "If is set to a value of 0, buffer swaps are not + * synchronized to a video frame." + * + * Implementation note: It is possible to enable triple buffering behaviour + * by not using XCB_PRESENT_OPTION_ASYNC, but this should not be the default. + */ + if (priv->swap_interval == 0) + options |= XCB_PRESENT_OPTION_ASYNC; + back->busy = 1; back->last_swap = priv->send_sbc; xcb_present_pixmap(c, @@ -1578,7 +1590,7 @@ dri3_swap_buffers(__GLXDRIdrawable *pdraw, int64_t target_msc, int64_t divisor, None, /* target_crtc */ None, back->sync_fence, - XCB_PRESENT_OPTION_NONE, + options, target_msc, divisor, remainder, 0, NULL); -- 2.30.2