Bug 200633 - [Regression] VGA not being detected with R9 380 using AMDGPU after 4.17 kernel update.
Summary: [Regression] VGA not being detected with R9 380 using AMDGPU after 4.17 kerne...
Status: NEW
Alias: None
Product: Drivers
Classification: Unclassified
Component: Video(DRI - non Intel) (show other bugs)
Hardware: x86-64 Linux
: P1 low
Assignee: drivers_video-dri
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2018-07-23 20:03 UTC by syboxez
Modified: 2018-07-25 17:43 UTC (History)
3 users (show)

See Also:
Kernel Version: 4.17
Subsystem:
Regression: Yes
Bisected commit-id:

Attachments
dmesg log (69.92 KB, text/plain)
2018-07-25 17:42 UTC, syboxez 		Details
Xorg log (48.86 KB, text/plain)
2018-07-25 17:43 UTC, syboxez 		Details
Add an attachment (proposed patch, testcase, etc.)

Description syboxez 2018-07-23 20:03:19 UTC 
OS: Debian Sid
Kernel: 4.17.8
GPU: AMD R9 380
Mesa version: 18.1.4

After upgrading from 4.16 to 4.17 (this bug was also reproduced on 4.18-RC3), xrandr reports VGA displays (normally DVI-I-1 in my case) as digital displays (DVI-D-1), and will display a black screen on the monitor I am attempting to use. In 4.16, it worked perfectly. Booting the system with the 4.16 kernel resolves the issue.

I will be happy to collect any useful logs upon request, as I'm not too sure what to look for.
Comment 1 Michel Dänzer 2018-07-24 07:51:01 UTC 
Please attach the dmesg output and Xorg log file corresponding to the problem.

amdgpu.dc=0 on the kernel command line might serve as a workaround for the time being.
Comment 2 syboxez 2018-07-24 17:49:25 UTC 
dmesg: https://ghostbin.com/paste/7pyty
Xorg: https://ghostbin.com/paste/38zyy

amdgpu.dc=0 does indeed make the issue go away, so I'm guessing DC was turned on by default for Tonga in this kernel.
Comment 3 Michel Dänzer 2018-07-25 07:51:52 UTC 
(In reply to syboxez from comment #2)
> dmesg: https://ghostbin.com/paste/7pyty
> Xorg: https://ghostbin.com/paste/38zyy

Thanks, but please attach files here directly instead of referencing an external pastebin site.
Comment 4 syboxez 2018-07-25 17:42:48 UTC 
Created attachment 277521 [details]
dmesg log
Comment 5 syboxez 2018-07-25 17:43:16 UTC 
Created attachment 277523 [details]
Xorg log
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