external display unrecognized

[gkaldev]

I have a USB-C to display port cable. I'm unable to output anything from the Pixel to an external monitor. I'm using the v4.8-1 build (first build I tried connecting external monitor).

xrandr output with monitor connected: Screen 0: minimum 8 x 8, current 2560 x 1700, maximum 32767 x 32767 eDP1 connected primary 2560x1700+0+0 (normal left inverted right x axis y axis) 272mm x 181mm 2560x1700 60.0*+ 2048x1536 60.0
1920x1440 60.0
1856x1392 60.0
1792x1344 60.0
1920x1200 60.0
1920x1080 59.9
1600x1200 60.0
1680x1050 60.0 59.9
1600x1024 60.2
1400x1050 60.0
1280x1024 60.0
1440x900 59.9
1280x960 60.0
1360x768 59.8 60.0
1152x864 60.0
1024x768 60.0
800x600 60.3 56.2
640x480 59.9
DP1 disconnected (normal left inverted right x axis y axis) DP2 disconnected (normal left inverted right x axis y axis) HDMI1 disconnected (normal left inverted right x axis y axis) HDMI2 disconnected (normal left inverted right x axis y axis) VIRTUAL1 disconnected (normal left inverted right x axis y axis)

[raphael]

Have you tried the other USB C port? Also try flipping the plug. It's not symmetric even though they would like you to believe it is... I use an external monitor everyday just fine but I have to plug it a certain way (I put a sticker on the plug to know which side is "up").

[gkaldev]

Tried both ports and orientations, but unfortunately no luck. Maybe my cable is defective, albeit new?

[samuellsk]

dont know whenever you are new to the whole pixel segment, i m using 2015 ls model, gallium os, with kernel 4.7.2 from here (raphael), was using it for a while (and older kernels also).

First time i used usb c / hdmi (from hootoo company) , it did not show anything, then i simply "flip" the adapter upside down and it started to work.

did not tried kernel 4.8 as i see there are more problems with it. maybe yours usb c / hdmi is not supported ? i tried usb 3.0 / hdmi / vga (from dell notebooks, becouse we have a lot of those around) , but it was not showing anything, but my hootoo adapter is working perfectly.

[nilswiersma]

Have you tried having it plugged in before booting? Also I sometimes have to fiddle with it a little, as in wiggle it around, plugging it not in all the way / slowly, things like this. And the aforementioned also applied to my cable. I'm not sure if it is because it's some cheap cable, but this usually fixes it for me.

[samuellsk]

well, it sounds like a cheap cable, if you need to fiddle around to make it work.

to your question, i think i did not, i acctualy do not remember when i booted last time (according to uptime, 7 days ago , must have been updates or something...). I m usualy sleeping , carry it to home and back to work. At work i have adapter so with one cable i plug everything (power , ethernet , mouse, personal backup drives).

edit: did not know what it should do, but powered off and powered back up. My adapter (and display nearby connected to it) came online as soon as i saw gallium os logo rotating

[chrisrossx]

Could you share which setup you have at work to-do that? I just returned a strategy mst dock that I couldn't get to work. It used a megachip chipseg, I was going to exchange the dock for one with a display link chipset, but haven't found one with power delivery. Thanks.

On Oct 11, 2016 03:07, "samuellsk" notifications@github.com wrote:

well, it sounds like a cheap cable, if you need to fiddle around to make it work.

to your question, i think i did not, i acctualy do not remember when i booted last time (according to uptime, 7 days ago , must have been updates or something...). I m usualy sleeping , carry it to home and back to work. At work i have adapter so with one cable i plug everything (power , ethernet , mouse, personal backup drives).

— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/raphael/linux-samus/issues/162#issuecomment-252867843, or mute the thread https://github.com/notifications/unsubscribe-auth/AHS_L42ROUGuSKh5VxZKXt_condvhcoLks5qy1_1gaJpZM4KRiFs .

[samuellsk]

chrisrossx , i m using this one https://www.amazon.com/HooToo-Shuttle-Delivery-Charging-Output/dp/B019R9ILTG/ref=sr_1_10?s=electronics&ie=UTF8&qid=1476196562&sr=1-10&keywords=hootoo

hootoo shuttle with power delivery :) , using original chromebook usb c adapter, and of course buy an extension cable. I bought mine at apple store (i did not wanted to be risking getting "bad" cable)

for ethernet (usb to ethernet adapter which is pluged into hootoo hub) i m using speed dragon http://www.newegg.com/Product/Product.aspx?Item=9SIA6J330U2690 , pretty old one :) , but there should not be much of a problem , i m carrying some sort of noname as a backup (in my notebook bag just in case) and it works too.

oh, btw, external display is here for me only to show others stuff. I m using internal display in native resolution and my boss and a other colegues have problems reading from it :)

hw: pixel 2015 ls os: as i mention before gallium os (2.0, not vannila, went through upgrade from 1.0) kernel: raphael 4.7.2 other tweaks: non there is an sd card 512gb uhs 3 , there are virtual boxes which i m using daily (boots quite fine and works fine too).

[gkaldev]

Did some additional investigation here. When I use a USB-C to HDMI dongle, I'm able to successfully connect an external monitor (although it seems only the right side USB-C port works). Oddly, it shows up in xrandr as "DP2" instead of HDMI1/HDMI2 as I thought it would. However, using a USB-C to display port cable does not work, as described in the original post. For others who have external monitors working, are you using a USB-C to HDMI cable or USB-C to display port cable? Is anyone able to get it working using the latter?

[dsem]

I've successfully had two external monitors working under various scenarios:

Scenario 1: USB-C -> display port cable connected to one monitor, then daisy chained from the first monitor to a second monitor. This is sometimes a little wonky and I can only get the second monitor to show up if I unplug it's power, plug the usb->displayport cable into the first monitor, then plug the power to the second monitor in.

Scenario 2 Using both USB-C ports, I have USB-C to display port on one monitor and then USB-C to USB-C to another monitor. The USB-C to USB-C also delivers power to the pixel. Both monitors are 4k and this scenario does result in a some random hard freezes when refreshing the displays (such as when waking up from suspend). I think the freezes are less frequent when I disable the built-in monitor.