I posted a patch series for -modesetting that fixes this issue, and also adds TearFree support: https://gitlab.freedesktop.org/xorg/xserver/merge_requests/24
The patch series from Ville (https://patchwork.freedesktop.org/series/49663/) will however be what you are looking for, as it will not reduce the performance at all.
I posted a patch series for -modesetting that fixes this issue, and also adds TearFree support: https:/ /gitlab. freedesktop. org/xorg/ xserver/ merge_requests/ 24
The patch series from Ville (https:/ /patchwork. freedesktop. org/series/ 49663/) will however be what you are looking for, as it will not reduce the performance at all.