Hi Gunnar,
on a RPi4B with 8G RAM and two Full HD displays connected I am running
bookworm. After upgrading firefox (102.15.1esr-1~deb12u1 to
115.3.0esr-1~deb12u1) recently, it failed to start and threw multiply:
```
DRM_IOCTL_MODE_CREATE_DUMB failed: Cannot allocate memory
Failed to create scanout resource
```
After setting CMA=128M in /etc/default/raspi-firmware, update-initramfs
and reboot firefox started properly and is usable.
```
# grep -i cma /proc/meminfo
CmaTotal: 131072 kB
CmaFree: 48612 kB
```
And if I run mpv (with CMA=128M) in addition to firefox, I occasionally
also get the above error.
I suggest removing the notice in /etc/default/raspi-firmware concerning
RPi4, or referring to this bug, and maybe updating other docs and the
image when you find time, because I guess firefox is a frequently used
application on this device and if it fails, it would push off users.
Cheers,
ibu
