Dear Community,
We are facing an issue on HDMI connection detection:
When the cable is connected once, the signal cable_state toggles from plugout to plugin, but when we disconnect the cable, the cable_state remains in plugin state.
Linux version: 5.4
To reproduce:
root@apalis-imx6:~# cat /sys/devices/soc0/soc.0/20e0000.hdmi_video/cable_state
plugout
Voltage : 0.16v on HPD pin 232
From iMX6 datasheet : Hot plug detect low range — 0 — 0.8 V
→ OK
root@apalis-imx6:~# cat /sys/devices/soc0/soc.0/20e0000.hdmi_video/cable_state
plugin
Voltage : 2,9v on HPD pin 232
From iMX6 datasheet : Hot plug detect high range — 2.0 — 5.3 V
→ OK
root@apalis-imx6:~# cat /sys/devices/soc0/soc.0/20e0000.hdmi_video/cable_state
plugin
Voltage : 0.16v on HPD pin 232
From iMX6 datasheet : Hot plug detect low range — 0 — 0.8 V
→ NOK
dmesg log when the monitor is connected:
root@apalis-imx6:~# [ 86.462202] mxc_hdmi 20e0000.hdmi_video: Read EDID again
[ 86.675867] mxc_sdc_fb fb.18: 640x480 h_sync,r,l: 96,16,48 v_sync,l,u: 2,10,33 pixclock=25175000 Hz
[ 86.753395] mxc_hdmi 20e0000.hdmi_video: create default modelist
[ 86.775371] mxc_sdc_fb fb.18: 640x480 h_sync,r,l: 96,16,48 v_sync,l,u: 2,10,33 pixclock=25175000 Hz
[ 86.841942] mxc_sdc_fb fb.18: 1280x720 h_sync,r,l: 40,110,220 v_sync,l,u: 5,5,20 pixclock=74250000 Hz
Is that behavior known from your side ?
Br, Vincent