Bug 258405 - rpib4 : display resolution 4k mode and network interface does not properly work together
Summary: rpib4 : display resolution 4k mode and network interface does not properly wo...
Status: New
Alias: None
Product: Base System
Classification: Unclassified
Component: arm (show other bugs)
Version: CURRENT
Hardware: arm64 Any
: --- Affects Only Me
Assignee: freebsd-arm (Nobody)
Depends on:
Reported: 2021-09-10 15:27 UTC by x11max1@unitybox.de
Modified: 2021-09-10 21:00 UTC (History)
1 user (show)

See Also:

network interface genet0 and display resolution 1920x1280 only (479.57 KB, image/jpeg)
2021-09-10 15:27 UTC, x11max1@unitybox.de
no flags Details

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Description x11max1@unitybox.de 2021-09-10 15:27:07 UTC
Created attachment 227806 [details]
network interface genet0 and display resolution 1920x1280 only

I own several rpib4 model b and one of them i use as a desktop pc connected to a 4k monitor.

Installed is FreeBSD version 13.0.
FreeBSD rpi4b 13.0-CURRENT FreeBSD 13.0-CURRENT #14 r370524: Thu Sep  9 08:46:11 CEST 2021     root@rpi4b:/usr/obj/usr/src/arm64.aarch64/sys/GENERIC  arm64

There are some problem with the network interface and display relosolution.

If rpib4 is configured to load a display resolution in 4K mode (3840x2160) the network interface is not coming up, means the network interface named "genet0" is no more in the device tree and could not be loaded.

But without 4k mode the network interface is coming up. With this configuration the max display resolution is "1920x1280" i can use with rpib4. 

Somewhere else have observe this behaviour ?

If starting up the same rpib4 using raspberry OS all is fine.

The problem seems to be located in the file: bcm2711-rpi-4-b.dtb 
TŚtaarting in 4k mode the network interface "genet0" is configured out after boot process is done. Don't know see why.

/usr/local/share/rpi-firmware comes with /usr/local/share/rpi-firmware.
-rw-r--r--  1 root  wheel    49090 Mar  3  2021 bcm2711-rpi-4-b.dtb

stefanev@rpi4b> file -s bcm2711-rpi-4-b.dtb
bcm2711-rpi-4-b.dtb_ORIG: Device Tree Blob version 17, size=49090, boot CPU=0, string block size=4026, DT structure block size=44992

But i have replaced this file with an older one, that makes it possible to root up rpib4.

-rwxr-xr-x  1 root  wheel  40659 Mar 13 13:59 bcm2711-rpi-4-b.dtb
stefanev@rpi4b> file -s bcm2711-rpi-4-b.dtb                                                                                                                                     /boot/msdos
bcm2711-rpi-4-b.dtb: Device Tree Blob version 17, size=40659, boot CPU=0, string block size=3643, DT structure block size=36944

stefanev@rpi4b> cat config.txt                                                                                                                                                  /boot/msdos
# enable audio (loads snd_bmc2835)

##### START audio over hdmi #####
# You need them both set because hdmi_group=1 tells the kernel we are using CEA 
# mode (for TV's, has sound) instead of DMT mode(for monitors, no sound) and 
# hdmi_drive=2 tells the kernel to use HDMI if available. (HDMI mode has sound, DVI does not.)
##### END audio over hdmi #####
#### with this setting rpib4 won't start up, boot process stucks if loading 4k
#hdmi_cvt 3840 2160 60
Comment 1 Klaus Küchemann 2021-09-10 21:00:37 UTC
Currently there's no hardware acceleration driver implemented for the RPI4.
So the limit is 1920x1280 for the frame buffer driver.
fb0: <BCM2835 VT framebuffer driver> on simplebus0