Hi Harry, A kernel bug report was opened against Ubuntu [0]. After a kernel bisect, it was found the following commit introduced the bug:
commit 4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c Author: Harry Wentland <[email protected]> Date: Tue Sep 12 15:58:20 2017 -0400 drm/amd/dc: Add dc display driver (v2) The regression was introduced as of v4.15-rc1 and still exists in current mainline. The commit does not need to be reverted to resolve the bug. Disabling the CONFIG_DRM_AMD_DC_PRE_VEGA option makes the bug go away. I was hoping to get your feedback, since you are the patch author. Do you think gathering any additional data will help diagnose this issue? Thanks, Joe [0] http://pad.lv/1761751 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1761751 Title: Black screen on 18.04 + AMD RX460 Status in linux package in Ubuntu: In Progress Status in linux source package in Bionic: In Progress Bug description: I've been running 16.04 + hwe kernel 4.15 for a while now and recently I'm now having a black screen instead. I've also tried an 18.04 daily live USB stick, which has the same issue. It probably started during an upgrade this week or last week. As a start I'm blaming the Linux kernel since booting a 4.13 kernel works just fine. Known faulty kernel versions are: * linux-image-4.15.0-041500-generic (mainline kernel), * linux-image-4.16.0-041600-generic (mainline kernel), * linux-image-4.15.0-13-generic (Ubuntu kernel), * whatever comes with 18.04 daily live USB stick as of 20180404. Not sure how to best collect logs and system information for you since I'm not used to debugging black screens, so I'm just attaching lspci as a start. EDIT: Workaround found by adding "amdgpu.dc=0" to kernel boot parameters. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1761751/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp

