Comment 27 for bug 1946368

@juergh with this new kernel I no longer see the flip_done timed out message, but HDMI still dies and the boot process hangs right after plymouth starts up.

```
ext4
Thu Jan 1 00:00:09 UTC 1970
writable: recovering journal
writable: clean, 159978/929200 files, 1595477/3751163 blocks
-.mount
blk-availability.service
dev-hugepages.mount
dev-mqueue.mount
sys-kernel-debug.mount
sys-kernel-tracing.mount
kmod-static-nodes.service
systemd-modules-load.service
systemd-remount-fs.service
ufw.service
swapfile.swap
systemd-journald.service
sys-fs-fuse-connections.mount
sys-kernel-config.mount
systemd-growfs@-.service
systemd-random-seed.service
systemd-sysusers.service
systemd-sysctl.service
systemd-tmpfiles-setup-dev.service
keyboard-setup.service
systemd-journal-flush.service
lvm2-monitor.service
snap-bare-5.mount
snap-core-11803.mount
snap-core20-1171.mount
snap-firefox-633.mount
snap-gnome\x2d3\x2d38\x2d2004-78.mount
snap-gtk\x2dcommon\x2dthemes-1519.mount
snap-snap\x2dstore-555.mount
systemd-udevd.service
systemd-udev-trigger.service
plymouth-start.service
[ 15.442712] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43456-sdio for chip BCM4345/9
[ 15.725950] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43456-sdio for chip BCM4345/9
[ 15.738824] brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43456-sdio for chip BCM4345/9
[ 15.760840] brcmfmac: brcmf_c_preinit_dcmds: Firmware: BCM4345/9 wl0: May 14 2020 17:26:08 version 7.84.17.1 (r871554) FWID 01-3d9e1d87
```