[Pkg-raspi-maintainers] Bug#980536: raspi-firmware: CMA=64M too small for 4K display and vc4.ko in 5.10 kernel

[Ryutaroh Matsumoto]

Package: raspi-firmware
Version: 1.20210111+ds-2
Severity: normal

Dear Maintainer,

Linux 5.10.x enables vc4.ko for Raspberry Pi, and it enables
4K resolution on raspi 4B.
When gdm3 display manager starts, it consumes roughly 100 MB of
CMA, as

# grep -i cma /proc/meminfo 
CmaTotal:         262144 kB
CmaFree:          143008 kB

When CMA is insufficient, the screen becomes blank and kernel logs
kernel: [drm:vc4_bo_create [vc4]] *ERROR* Failed to allocate from CMA:
which is also discussed at
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=968181#60

I am using CMA=256M at 128M in /etc/default/raspi-firmware.
The default 64M does not work for high resolution displays and 5.10 kernel.


Best regards, Ryutaroh Matsumoto

-- System Information:
Debian Release: bullseye/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'unstable'), (1, 'experimental')
Architecture: arm64 (aarch64)

Kernel: Linux 5.10.9 (SMP w/4 CPU threads)
Kernel taint flags: TAINT_CRAP, TAINT_UNSIGNED_MODULE
Locale: LANG=C.UTF-8, LC_CTYPE=C.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages raspi-firmware depends on:
ii  dosfstools  4.1-2
ii  dpkg        1.20.7.1

raspi-firmware recommends no packages.

raspi-firmware suggests no packages.

-- Configuration Files:
/etc/default/raspi-firmware changed:
CONSOLES=""
ROOTPART="LABEL=RASPIROOT"
CMA=256M at 128M


-- no debconf information