1

I've installed Ubuntu desktop on a Raspberry PI 4. To my surprise HDMI-CEC is not working. Is is it a known bug ?

$ sudo apt-get install cec-utils libcec-dev

$ cec-client -l


LibCEC version: 6.0.2 compiled on Linux-4.15.0-109-generic ... , features: P8_USB, DRM, p8_detect, randr, Exynos, AOCEC
Found devices: NONE

Ubuntu version:

$ lsb_release -a
Distributor ID: Ubuntu
Description: Ubuntu 20.10
Release: 20.10
Codename: groovy

$ uname -a
Linux <redacted-user> 5.8.0-1007-raspi #10-Ubuntu SMP PREEMPT Thus Nov 5 17:52:40 UTC 2020 aarch64 aarch64 GNU/Linux
Mihai
  • 111
  • What is "the latest version"? – Pilot6 Nov 28 '20 at 16:24
  • I've updated my question with information from lsb_release. I thought the cec-client command gave hints about the linux/kernel version. – Mihai Nov 28 '20 at 16:34
  • How happened that kernel version is 4.15 on Ubuntu 20.10? – Pilot6 Nov 28 '20 at 17:02
  • I don't know..maybe libcec is reporting a wrong kernel version? I also added $uname -a in my question. – Mihai Nov 28 '20 at 20:54
  • I removed and installed cec-utils again and the result is same. The computer is a Raspberry PI 4 with ARM processor. – Mihai Nov 28 '20 at 21:12
  • after the apt install should you not configure it 1st? cec-ctl it was iirc?? and cec-compliance to show the result – Rinzwind Nov 28 '20 at 21:45
  • cec-ctl errors out with Failed to open /dev/cec0: no such file or directory. I've also checked /dev/ and there is no cec* device mounted there. – Mihai Nov 28 '20 at 22:17
  • Can't answer your question, but here are two things that often go wrong with CEC on Raspberry. First, CEC is implemented using the GPU, so you must be a member of the video group to access CEC. If sudo cec-client -l shows results, you know that access rights are your problem. Second, HDMI on Raspberry can be finicky: you may need to add hdmi_force_hotplug=1 to your config.txt and reboot to make sure the Raspberry picks up the HDMI port. Raspberry uses VCHIQ for CEC so you probably won't see a /dev/cec0. – BertD Dec 16 '20 at 22:45

0 Answers0