DP Flickering Issue

Autonomous Machines Jetson & Embedded Systems Jetson Nano
#1

Hi,

We discovered the DP output has flickering issue with AOC U2868PQU. Please see the attached video.

The JetPack version is JetPack 4.5.1.

The dmesg is also attached. It has some “defer” logs which might cause the issue.
DP_AOC_Flicker_dmesg.txt (87.8 KB)

[    1.819245] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 6
[    1.820483] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 5
[    1.822363] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 6
[    1.823604] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 5
[    1.825483] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 6
[    1.826722] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 5
[    1.828603] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 6
[    1.829841] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 5
[    1.831721] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 6
[    1.832959] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 5
[    1.834840] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 6
[    1.836079] tegradc tegradc.1: dp: aux read defer (0x10020000) -- 5
[    1.839114] tegradc tegradc.1: tegra_dp_get_bpp: vmode=0x200000 did not specify bpp
[    1.850615] tegradc tegradc.1: nominal-pclk:533333000 parent:533278125 div:1.0 pclk:533278125 527999670~581332970

Please help advise.

#3

Is this custom board or NV devkit?

#4

Hi WayneWWW,

Thanks!
This issue happens on our custom board.

#5

Will you see same behavior with same monitor on the devkit?

#6

Hi WayneWWW,

This issue is reported by our customer. So we don’t have the monitor to test.
Currently, “dp: aux read defer” is the only log difference compared with other normal monitor.
Is there anything we can do from the hardware signal aspect?

#7

Please ask your customer to try this monitor on devkit and see if same log and error coming out.

#8

Hi WayneWWW,

Sorry, our customer does not have devkit board so they don’t have chance to test it.
However, they did some cross validations and found this issue only happens on our latest custom board.
Could you suggest any NVIDIA hardware design guide regarding DP for us?

#9

Did you ever check the tuning guide document and do the dp port tuning?