tried the vc4... dtoverlay -- no difference
its kernel 5.10.27-4-arch i think, as 5.10.27-1-arch is working.
Output on failing rpi-4
X.Org X Server 1.20.11
X Protocol Version 11, Revision 0
Build Operating System: Linux Archlinux
Current Operating System: Linux server-pi 5.10.25-5-ARCH #1 SMP Wed Mar 31 22:58:05 UTC 2021 armv7l
Kernel command line: coherent_pool=1M 8250.nr_uarts=1 snd_bcm2835.enable_compat_alsa=0 snd_bcm2835.enable_hdmi=1 video=HDMI-A-1:1280x1024M@60 smsc95xx.macaddr=DC:A6:32:85:CD:72 vc_mem.mem_base=0x3ec00000 vc_mem.mem_size=0x40000000 root=/dev/mmcblk0p2 rw rootwait console=ttyAMA0,115200 console=tty1 selinux=0 plymouth.enable=0 smsc95xx.turbo_mode=N dwc_otg.lpm_enable=0 kgdboc=ttyAMA0,115200 audit=0
Build Date: 13 April 2021 09:16:41PM
Current version of pixman: 0.40.0
Before reporting problems, check
http://wiki.x.org to make sure that you have the latest version.
Markers: (--) probed, (**) from config file, (==) default setting,
(++) from command line, (!!) notice, (II) informational,
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(==) Log file: "/var/log/Xorg.0.log", Time: Mon Apr 19 09:51:35 2021
List of video drivers:
fbturbo
modesetting
fbdev
vesa
No devices to configure. Configuration failed.
(EE) Server terminated with error (2). Closing log file.
#
modprobe -v fbturbo
modprobe: FATAL: Module fbturbo not found in directory /lib/modules/5.10.25-5-ARCH
server-pi:root ~ # modprobe -v fbdev
modprobe: FATAL: Module fbdev not found in directory /lib/modules/5.10.25-5-ARCH