On 08/09/2020 10:13, Timo Ketola wrote: > On 8.9.2020 10.57, Hans Verkuil wrote: >> I suspect that this is a BIOS-only implementation that just does the bare minimum >> for wake up and standby (if enabled). > > What does it mean? Is it just that BIOS does not report about it to the OS? If it was implemented with GPIOs, shouldn't it still be possible to write a driver for it - in theory - if we somehow were > able to find out the GPIOs? Usually CEC is handled by a microcontroller or a specialized CEC chip. It's rare to see a pure GPIO implementation. So it is typically not possible to get access to it if it is all handled in the BIOS. At least, I've never seen it. I also suspect that what they call 'CEC' is a really cut-down implementation, just enough to receive/transmit wake-up and standby messages. Sadly, without any documentation there isn't anything that can be done about this. If you want to support CEC under linux, then go with a Pulse-Eight USB CEC adapter: this is fully supported by linux. Regards, Hans > > Unfortunately, I don't know too much about modern PCs at this level. > > Thanks for looking at this! > > -- > > Timo
