diff options
| -rw-r--r-- | src/loader/loader_dri3_helper.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/src/loader/loader_dri3_helper.c b/src/loader/loader_dri3_helper.c index 6db8303d26d..f0ff2f07bde 100644 --- a/src/loader/loader_dri3_helper.c +++ b/src/loader/loader_dri3_helper.c @@ -370,9 +370,17 @@ dri3_handle_present_event(struct loader_dri3_drawable *draw, * checking for wrap. */ if (ce->kind == XCB_PRESENT_COMPLETE_KIND_PIXMAP) { - draw->recv_sbc = (draw->send_sbc & 0xffffffff00000000LL) | ce->serial; - if (draw->recv_sbc > draw->send_sbc) - draw->recv_sbc -= 0x100000000; + uint64_t recv_sbc = (draw->send_sbc & 0xffffffff00000000LL) | ce->serial; + + /* Only assume wraparound if that results in exactly the previous + * SBC + 1, otherwise ignore received SBC > sent SBC (those are + * probably from a previous loader_dri3_drawable instance) to avoid + * calculating bogus target MSC values in loader_dri3_swap_buffers_msc + */ + if (recv_sbc <= draw->send_sbc) + draw->recv_sbc = recv_sbc; + else if (recv_sbc == (draw->recv_sbc + 0x100000001ULL)) + draw->recv_sbc = recv_sbc - 0x100000000ULL; /* When moving from flip to copy, we assume that we can allocate in * a more optimal way if we don't need to cater for the display |