rob,
Do we need few other changes in mesa other than ctx->batch patch for 19.1.1 version?
i tried this patch https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3700 on mesa-19.1.1 in debian
But after the boot in hdmi, only mouse cursor(able to move the positions in display) and black blank screen
sudo apt-get build-dep libgl1-mesa-dri
sudo apt-get source libgl1-mesa-dri
sudo apt-get install fakeroot gcc
cd mesa-19.1.1
this will download the mesa-19.1.1 src , added the ctx->batch to be NULL patch
dpkg-buildpackage -b -us -uc
sudo dpkg -i libgl1-mesa-dri_19.1.1-1+linaro2_arm64.deb
sudo dpkg -i libgl1-mesa-dri-dbgsym_19.1.1-1+linaro2_arm64.deb
after reboot blank screen and mouse cursor
regards,
vinaysimha