[Pkg-raspi-maintainers] Bug#996937: raspi-firmware: possibly disable cma= setting on Pi CM4 as well

[Cyril Brulebois]

Package: raspi-firmware
Version: 1.20210303+ds-2
Severity: normal

Hi,

Looking at #980536, and if I'm reading between the lines correctly, the
whole Pi 4 family should have no cma= setting, and we should be skipping
it on the Compute Module 4 the same way we do on the Pi 4.

The current check happens with:

    grep -q 'Raspberry Pi 4' /proc/device-tree/model

If my understanding is correct, we should be additionally checking:

    grep -q 'Raspberry Pi Compute Module 4' /proc/device-tree/model

This would avoid re-adding cma=$CMA (with CMA defaulting to 64M) on the
CM4, which the image-specs build disabled initially, when producing the
image with `make raspi_4_bullseye.img`.


If the setting is confirmed to be extraneous, and is gotten rid of,
it would reduce the differences between before/after first boot's
cmdline.txt (see also [1]).

 1. https://salsa.debian.org/raspi-team/image-specs/-/issues/57


I'm happy to propose a tested patch once I have a confirmation regarding
the “should we do it” part. :)


Cheers,
-- 
Cyril Brulebois -- Debian Consultant @ DEBAMAX -- https://debamax.com/