5Ghz WiFi blocked by vc4.ko on kernel 5.10.12 on RPi4B 8GB

[Maxime Ripard]

Hi,

On Wed, Feb 03, 2021 at 03:18:43PM +0900, Ryutaroh Matsumoto wrote:
> > * I am able to connect my 2.4 GHz WiFi, while I am unable to connect 5 GHz.
> > * My HDMI output is 3840x2160 at 30 Hz.
> 
> "ping" packets do not reach to another host on 2.4 GHz WiFi,
> while NetworkManager or systemd-networkd connects to SSID of 2.4GHz.
> For 5GHz with vc4.ko, NetworkManager does not connect to the SSID of 5GHz,
> so the symptom is better with 2.4GHz.
> The symptom of 2.4GHz is the same both with vc4 and without vc4.
> 
> "iw dev wlan0 info" prints as follows, but ping packets do not reach.
> Interface wlan0
> 	ifindex 3
> 	wdev 0x1
> 	addr dc:a6:32:bb:99:da
> 	ssid *****
> 	type managed
> 	wiphy 0
> 	channel 4 (2427 MHz), width: 20 MHz, center1: 2427 MHz
> 	txpower 31.00 dBm
> 
> The only usable configuration is WiFi 5GHz connection with module_blacklist=vc4...

This is weird. As far as I know, there's no overlap in the 2160p at 30Hz
and the 5GHz frequencies range. The TMDS rate seems to be 2.9GHz, so
we're fairly far off.

And does fkms (or the simplefb driver at 1440p) show the same behaviour?

Maxime
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 228 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-rpi-kernel/attachments/20210210/c15205dc/attachment.sig>