Subject: [alpine-devel] VGA hot plug not work on a Intel J3160 mini PC

From: duanyao <[email-masked]>
Date: Thu, 2 Nov 2017 17:44:38 +0800

Hi,

I'm testing Alpine 3.6.2 (text console mode) on a mini PC with a Intel 
J3160 CPU.

It's using the integrated GPU and connected with a VGA display (Dell 
S2009WB).

If I hot plug the display, it will not work anymore (the display says 
there is no signal). The system is still running, and I can ssh into it.

There is nothing shown in dmesg or syslog when plug out or plug in the 
display.

However, display hot plug works fine in BIOS settings (AMI) and grub2, 
and also in Ubuntu 16.04 and Win 10 PE on this mini PC.

VGA hot plug also works with Alpine 3.6.2 on some other PC (e.g. Dell 
3020), so it seems a problem with this special hardware+OS

combination.

Any suggestion to investigate this issue? Thanks!

Duan, yao

---
Unsubscribe:  [email-masked]
Help:         [email-masked]
---

---

From: Jeff Pohlmeyer <[email-masked]>
Date: Thu, 2 Nov 2017 08:17:28 -0500

On Thu, Nov 2, 2017 at 4:44 AM, duanyao <[email-masked]> wrote:

> I'm testing Alpine 3.6.2 (text console mode) on a mini PC with a Intel J3160
> CPU.

> If I hot plug the display, it will not work anymore (the display says there
> is no signal). The system is still running, and I can ssh into it.

If you can ssh into the machine, you might try running
some vbetool[1] commands to see if you can wake up the
display ("vbetool dpms on" or something)

If that works, next step would be to add a udev (or mdev)
rule[2] to run that command automatically when the monitor is
plugged in.

[1] https://git.alpinelinux.org/cgit/aports/plain/unmaintained/vbetool/APKBUILD
[2] https://wiki.archlinux.org/index.php/udev#Execute_on_VGA_cable_plug_in

-- Jeff

---