As you may guess, hdmi0-monitor.edid is the EDID for the monitor plugged into HDMI0 (the socket closest to the USB-C power port on the Pi4, and the socket closest to the uSD slot on the Pi400), whilst hdmi1-monitor.edid is the EDID for the monitor plugged into HDMI1. If you have no monitor connected to a socket, you'll still get an EDID file but it'll be 0 bytes. A valid EDID file should be 256 bytes (or more? I forget the details of EDID, but there's some extended blocks I vaguely recall).
Upload valid EDID files to https://www.edid.tv/edid/upload/binary/ if you wish (bear in mind this will share the serial # of your monitor but I don't think there's any particular security risk in that), and add the link here along with whether or not this particular monitor suspends successfully or not.
FYI, in case anyone wants to add their monitor (and whether it succeeds or fails at suspending with the Ubuntu raspi kernel) to this ticket:
$ cp /sys/devices/ platform/ gpu/drm/ card1/card1- HDMI-A- 1/edid hdmi0-monitor.edid platform/ gpu/drm/ card1/card1- HDMI-A- 2/edid hdmi1-monitor.edid
$ cp /sys/devices/
As you may guess, hdmi0-monitor.edid is the EDID for the monitor plugged into HDMI0 (the socket closest to the USB-C power port on the Pi4, and the socket closest to the uSD slot on the Pi400), whilst hdmi1-monitor.edid is the EDID for the monitor plugged into HDMI1. If you have no monitor connected to a socket, you'll still get an EDID file but it'll be 0 bytes. A valid EDID file should be 256 bytes (or more? I forget the details of EDID, but there's some extended blocks I vaguely recall).
Upload valid EDID files to https:/ /www.edid. tv/edid/ upload/ binary/ if you wish (bear in mind this will share the serial # of your monitor but I don't think there's any particular security risk in that), and add the link here along with whether or not this particular monitor suspends successfully or not.