Bug 212137

Summary: kernel NULL pointer dereference, black screen when using two graphics cards
Product: Drivers Reporter: Dennis Foster (mail)
Component: Video(DRI - non Intel)Assignee: drivers_video-dri
Status: RESOLVED CODE_FIX    
Severity: high CC: alexdeucher, mail
Priority: P1    
Hardware: x86-64   
OS: Linux   
Kernel Version: 5.11 Subsystem:
Regression: No Bisected commit-id:
Attachments: lspci -vvv
systemd journal

Description Dennis Foster 2021-03-08 17:39:41 UTC
Created attachment 295741 [details]
lspci -vvv

On linux v5.11 and above (up to 5.11.4) I cannot longer boot the system (GNOME/Wayland) using two graphics cards. It gets stuck with black screen with no response to keyboard/mouse.

In systemd journal there are some messages about kernel bug:

Mar 08 11:54:05 homeserver kernel: BUG: kernel NULL pointer dereference, address: 0000000000000008
Mar 08 11:54:05 homeserver kernel: #PF: supervisor read access in kernel mode
Mar 08 11:54:05 homeserver kernel: #PF: error_code(0x0000) - not-present page
Mar 08 11:54:05 homeserver kernel: PGD 0 P4D 0
Mar 08 11:54:05 homeserver kernel: Oops: 0000 [#1] PREEMPT SMP NOPTI
Mar 08 11:54:05 homeserver kernel: CPU: 6 PID: 608 Comm: gnome-shell Tainted: G OE 5.11.4-arch1-1 #1
Mar 08 11:54:05 homeserver kernel: Hardware name: Gigabyte Technology Co., Ltd. A320M-S2H/A320M-S2H-CF, BIOS F2 11/03/2020
Mar 08 11:54:05 homeserver kernel: RIP: 0010:drm_gem_handle_create_tail+0xcb/0x190 [drm]
Mar 08 11:54:05 homeserver kernel: Code: 00 48 89 df e8 c6 20 59 f4 45 85 e4 78 77 48 8d 5d 18 4c 89 ee 48 89 df e8 42 fe 00 00 89 c2 85 c0 75 3e 48 8b 85 40 01 00 00 <48> 8b 40 08 48 85 c0 74 0f 4c 89 ee 48 89 ef e8 81 8b 91 f4 85 c0
Mar 08 11:54:05 homeserver kernel: RSP: 0018:ffffb7a7c16bfd30 EFLAGS: 00010246
Mar 08 11:54:05 homeserver kernel: RAX: 0000000000000000 RBX: ffffa0eabe065090 RCX: 0000000000000001


Everything works perfectly fine using current LTS v5.10.21.
I am using Radeon RX 470 as a primary card, and the older ATI FirePro 2270 as a secondary one in order to provide two extra monitor outputs.

I've attached my lspci output as well as full systemd log.
Comment 1 Dennis Foster 2021-03-08 17:40:04 UTC
Created attachment 295743 [details]
systemd journal
Comment 2 Alex Deucher 2021-03-08 18:03:29 UTC
Likely the same issue as this:
https://www.spinics.net/lists/amd-gfx/msg59207.html
Comment 3 Alex Deucher 2021-03-08 19:18:05 UTC
Should be fixed with this patch:
https://patchwork.freedesktop.org/patch/423250/
Comment 4 Dennis Foster 2021-03-18 14:32:41 UTC
I can confirm now that the issue is fixed in recent 5.11.7 kernel.