My display port on custom carrier works only when I use a DP++ to HDMI conversion cable. when I put a standard DP to DP to my monitor, the monitor doesnt detect my display signal. I have tried several different monitors. wondering if its a pinmux setting issue, not sure which of 3 settings to use for native DP without conversion? are the settings defined somewhere?
hdmi_dpX_txdpX
dpX_txdpX
hdmiX_txdpX
where X = 0 - 3 for DP lane. hope this makes sense.
Does same monitor work fine when you are try it on NV developer kit?
Yes it does.
please review hardware design. Also, pinmux setting does not need to change if you flash default one provided by NV.
Does aux need pull up and pull down? I have replicated the devkit circuit. It outputs dp++ and works fine with converter cable. Just would rather it work with regular dp cable
Yes, please follow the Design Guide.
Thanks. the pullup/down is built into the PI3AUX221ZTAEX IC that is on my board which replicates the devkit circuit, so that isn’t my issue. what about the 3 choices in the pinmux? which one does the devkit use?
As you can see in the column “Devkit Usage” in pinmux sheet.
Yes, swap for HDMI. You can find answer in Design Guide.
I want a display port and I have the hardware according to this:
except note 1 and 2 are handled by an IC as per the devkit circuit.
I have the pinmux according to this: DP0_TXDPY → LNY where Y = 0,1,2,3. IMO the design guide has conflicting information as does the pinmux.
the usage column says DP0_TXDP2 for LANE0, but there is no choice for that…my choices are:
HDMI_DP0_TXDP0
DP0_TXDP0
HDMI0_TXDP2.
what is the correct choice for a direct display port connection.
Hi, in fact, pinmux does not really configure these DP/HDMI pins, you can just leave them as default. And just follow the hardware connections in Design Guide.
a bit more on this subject. changing the setting to any of those three settings, does not change anything about the dtsi file. all 3 settings create the exact same dtsi file which does not contain anything about the display mux. is this correct? should i be mapping it in a different way or place
That is correct… as our previous comment…
thanks. followed the hardware guide, still doesn’t work without a DP++ to HDMI converter.
Is same adapter able to work on NV devkit?
yes, the DP++ to HDMI works on both my system and devkit. devkit works straight DP but mine doesn’t.
more on this, it seems that direct DP connection works with each of the data lanes terminated with a 100 ohm resistor. why would this be? is there something I missed in the pinmux or some other setting that would cause this?
What’s the difference b/w your board and P3737_A04 board? As said, this is a board issue, you should find out difference and try to eliminate that. If any other 3rd-party device exists, you need to check with vendor for deeper question. For Jetson side, the DG and reference schematic is what we can guarantee, your design should follow that well.
