No HDMI monitor after updating to 28.2

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
6

I was using the back-quote character `, not the single quote character '. They look nearly identical. Back quoted content is executed prior to the rest of the command content…it is macro substitution. Your method is a bit better since it would work with sudo, whereas the one I quoted I drop into an sudo shell first.

Right after these lines in the log is where the mystery starts:

[     9.866] (**) NVIDIA(0): Option "ModeDebug"
[     9.866] (**) NVIDIA(0): Option "AllowEmptyInitialConfiguration" "true"
[     9.866] (**) NVIDIA(0): Enabling 2D acceleration
[     9.867] (--) NVIDIA(0): Valid display device(s) on GPU-0 at SoC
[     9.867] (--) NVIDIA(0):     DFP-0
[     9.867] (II) NVIDIA(0): NVIDIA GPU NVIDIA Tegra X2 (nvgpu) (GP10B) at SoC (GPU-0)
[     9.867] (--) NVIDIA(0): Memory: 8042776 kBytes
[     9.867] (--) NVIDIA(0): VideoBIOS:

Once that is done it should start quoting some information about the monitor, e.g., I have a ViewSonic which starts like this as it begins verbose description (this example is from one my monitors):

[     9.684] (--) NVIDIA(0): VideoBIOS:
[     9.684] (--) NVIDIA(GPU-0): ViewSonic VX2235wm (DFP-0): connected
[     9.684] (--) NVIDIA(GPU-0): ViewSonic VX2235wm (DFP-0): External TMDS
[     9.684] (--) NVIDIA(GPU-0): ViewSonic VX2235wm (DFP-0) Name Aliases:
[     9.684] (--) NVIDIA(GPU-0):   DFP
[     9.684] (--) NVIDIA(GPU-0):   DFP-0
[     9.684] (--) NVIDIA(GPU-0):   DPY-0
[     9.684] (--) NVIDIA(GPU-0):   HDMI-0
[     9.684] (--) NVIDIA(GPU-0):   DPY-EDID-124044e6-4814-6be6-88ed-c05985967430
[     9.684] (--) NVIDIA(GPU-0):   HDMI-0
[     9.684] (II) NVIDIA(GPU-0): 
[     9.684] (II) NVIDIA(GPU-0): --- Building ModePool for ViewSonic VX2235wm (DFP-0) ---
[     9.687] (II) NVIDIA(GPU-0):   Validating Mode "1680x1050_60":
...

That content is entirely from decoding the EDID. Your EDID checksum is good, and so we know the i2c is working correctly and that the EDID being sent is what was truly programmed in. However, there is something wrong with this EDID and the driver is treating the EDID as empty.

Is there anything odd with this monitor (perhaps the EDID has an issue with how it was constructed)? Is the EDID in any way custom? If not, then it may be a driver issue where the driver is dropping the EDID without using it (which is the case of how the EDID is being decoded).