Detect HDMI Hot plug at user space

HI, All

we have a question about HDMI Hotplug at Jeston NX

we want to provide user-space application a mechanism /event to know HDMI cable is plug or unplugged,
but we don’t konw how to implement at the driver level as well as user-space framework,
any code can we refer at Linux?

 Thanks for advance 


Moving into Jetson Xavier NX forum for resolution. Thanks


You could use the udev event to know what might be a hotplug event. Since hotplug will change the status of external-connection:disp-state, you can use it to tell.
If NAME of the extcon event matches to “external-connection:disp-state” consider it as HOTPLUG event.

thanks, could you name the driver who implemented this hotplug and change the status of external-connection:disp-state? our case is a little bit different with HDMI output which Jeston is HDMI source, our case is we have an HDMI to MIPI bridge chip on our carrier board, HDMI into jeton NX , so from Jeston side it is HDMI in , HDMI bridge chip is sink. This bridge chip provides HPD detection functionality, it notifies us by GPIO interrupt, we now only have a V4L driver to receive MIPI video from a bridge, but we need implement it at driver HPD first. right?

Please check our kernel source with path kernel/nvidia/drivers/video/tegra/dc. All the display kernel driver is in this location.