https://bugzilla.kernel.org/show_bug.cgi?id=212137

Bug ID: 212137 Summary: kernel NULL pointer dereference, black screen when using two graphics cards Product: Drivers Version: 2.5 Kernel Version: 5.11 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: high Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: mail@dennisfoster.us Regression: No

Created attachment 295741 --> https://bugzilla.kernel.org/attachment.cgi?id=295741&action=edit 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.