Hi,
. I am running the latest minimal image, just upgraded with the official procedure
. I have tested two screens and none of them is working, namely:
… Elecrow 5’’ 800x400 (this was tested working with BBB)
… Magedok 7’’ 1280x720 (tested working with other Linux boxes)
. I am using a miniDP <—> HDMI adapter branded BENFEI
. The screens power is taken from BBAI64 USB
. Both screen are not working, the only thing i see in the serial console is
[ 897.878222] cdns-mhdp8546 a000000.dp-bridge: get block[0] edid failed: -22
[ 897.885096] cdns-mhdp8546 a000000.dp-bridge: Failed to read EDID
[ 898.636909] cdns-mhdp8546 a000000.dp-bridge: Failed to read receiver capabilities
[ 905.058303] cdns-mhdp8546 a000000.dp-bridge: get block[0] edid failed: -22
@nmingotti My guess here is you’re running sans EDID info on either of the two monitors, so the BBAI-64 is outputting whatever default mode & clocks were deemed appropriate as default, which may or may not jive with your monitors.
BTW, I have my BBAI-64 outputting over a miniDP-DP cable to a Dell 24" 1920x1200 monitor. The output generally works, but it’s somewhat unstable – it appears to be losing sync sometimes, particularly during 60Hz kms fb swap sequences – the image is lost, only to return after a second or two. I do need to investigate this properly. It very much might be a similar ‘no EDID, just output at default mode & clocks and hope it works’ problem; if sufficiently close to what the monitor expects this might result in such intermittent losses of signal.
Maybe a directive like that may work also for BBAI64 but since /boot/uEnv.conf
is gone i don’t know where to try inform the system about the screen resolution+freq now.
Thank you Robert,
the only one i can have delivered to me tomorrow is this, I will let you know if it works as well . If it doesn’t i will stop the necessary time and stick to the model you tested.
. the active miniDP → HDMI arrived
. it is a half-success story
. the monitor Elecrow 5’ works
. the monitor Magedonk 7’ does not work. In the sense that
I off the BBAI64
I connect the monitor and power (usb) plug to the BBAI64
power on to BBAI64
=> Continuous reboot of the system
. The monitor model is T080A
. I made a further test connecting also an external power source, now IT WORKS.
. maybe the reboot was due too much power drawn out of the BBAI64
bye
Nicola