[R28.1] [TX2] Black lines appear on the screen

We have purchased TX2s by a plurality of times.
And installed L4T R28.1 from the same JetPack by my Ubuntu PC.
(It was downloaded once.)

The earlier TX2s are operating normally, but the later TX2s look wrong.
Some black lines are appear on the screen when it is set to UHD (3840 x 2160) resolution.

  • Several lines are in the fixed positions.
  • Several lines are in versatile positions.

If it is set to FullHD (1920 x 1080) resolution, they are operating normally.

I have confirmed 2 wrong TX2s with 2 different displays.

  • DELL U2713HMt (Rev A00, Jul 2014)
  • Panasonic TV TH-55DX750
    And 2 normal TX2s with LG 27UD58-B (Feb 2017)

What should I do ?

IMG_20170911_164443.jpg

IMG_20170911_164443.jpg

Hi mynaemi,

Please help check following value when black line appears.

cat /sys/kernel/debug/tegradc.0/stats  # tegradc number depends on your configuration.

Please try more tests on these tx2. Does the wrong TX2 not show black line with LG 27UD58-B?

Hi WayneWWW,

I appreciate your quick reply.

I tried it:

underflows: 0
underflows_a: 0
underflows_b: 0
underflows_c: 0
underflows_d: 0
underflows_h: 0
underflows_t: 0
underflows_frames: 0

It was same as normal TX2.

We have purchased more than 9 TX2s (I know).
3 TX2s were in July, 4 TX2s were in August and 2 TX2s were in September.

  • Jul: Normaly (tested 2 of them)
  • Aug: Wrong (tested 2 of them)
  • Sep: Normaly (tested 1 of them)

Does the wrong TX2 not show black line with LG 27UD58-B?

Sorry, I have not yet test in this case.

Hi WayneWWW,

I have installed L4T R28.1 to all the TX2s by my Ubuntu PC with LG27UD58-B.
I have not seen black lines during L4T installing.

TX2#1(Jul): Normal, another LCD, this is at another labo now.
TX2#2(Jul): Normal, LG 27UD58 and Panasonic DX750
TX2#3(Jul): (Not use, for spare equipment)
TX2#4(Aug): Wrong, DELL U2713HMt and Panasonic DX750, this is at labo next door.
TX2#5(Aug): Wrong, DELL U2713HMt and Panasonic DX750, this is at labo next door.
TX2#6(Aug): (Not tested, only installed L4T, next door)
TX2#7(Aug): (Not tested, only installed L4T, next door)
TX2#8(Sep): Normal, LG 27UD58
TX2#9(Sep): Normal, LG 27UD58

  • Panasonic DX750 TV with normal TX2 and wrong TX2 is same one.

Sorry that I don’t quite get the meaning of you record here. I guess you meant there are some devices that is out of test now.

Please make sure that all tegra is tested on all kinds of monitors to check if black line happens only on specific monitor/tegra.

Hi WayneWWW,

I’m sorry I didn’t make it clear enough.

We have only one “Panasonic DX750 TV”.
TX2#2 is normally operating with this DX750.
TX2#4 is wrong with this DX750.

What should I check or compare other than /sys/kernel/debug/tegradc.0/stats ?
e.g. XRandR ?

Ok, let me make a summary here.

The same TV (“Panasonic DX750 TV”) with tx2 #4 has black line but tx2 #2 not have.

Then I would like to know

  1. If the problem only happens on 4k -> Please modify the mode of Panasonic DX750 to 1080p or other resolution to check.

  2. If other TV/monitors also suffer the same problem with tx2 #4 and tx2 #2.

  3. How is rendering other stuff? Does the black line also occur?

Hi WayneWWW,

Thank you always for your kind support.

  1. If the problem only happens on 4k
    -> Please modify the mode of Panasonic DX750 to 1080p or other resolution to check.

(1) The other resolution
We have already tested 1920x1080, it was normaly operating.

(2) The other reflesh-rate
We set TX2 #4 to 30P by XRandR forced, then it was normaly operating.
(Panasonic DX750 TV)

xrandr --rate 30
  1. If other TV/monitors also suffer the same problem with tx2 #4 and tx2 #2.

TX2 #2 was normaly operating without XRandR (Panasonic DX750 TV).
Tomorrow, we will test TX2 #4 with BlackMagic DeckLink 4K Extreme 12G.

All of TX2s, using LG 27UD58 (supports 4K@60P), the reflesh-rate was 30P.
TX2 #8, using ASUS PB279 (supports 4K@60P), it was also 30P.

  1. How is rendering other stuff? Does the black line also occur?

What does this word “stuff” mean?
When black lines appear,
decoded 4k video using MultimediaAPI (renderer) breaks into fragments
without black lines.
Also, using GStreamer (gst-launch) captured video from camera device
breaks without black lines.

I suspect that the HDMI EDID negotiation has failed.
Sometimes TX1 and TX2 fails to get display specifications, and then it become very low resolution.
(When I connected LG display or HP display, sometimes TX1 and TX2 recognize it as SAMSUNG display.)

(When I connected LG display or HP display, sometimes TX1 and TX2 recognize it as SAMSUNG display.)
Do you hotplug tx2 to different monitors?

Hi mynaemi,

Is this still an issue to support?
Any further assistance required?

Thanks