I have a server that has been running Gentoo Linux for many years at home.
I almost never connect a screen to it, I access it via ssh.
I have noticed that for some time (months, years) probably after kernel upgrades (that I compile myself), if there is no monitor connected at boot time (which only happens after a power outage or kernel change), there is no display if I connect a monitor.
But if I boot with a monitor connected, everything works fine. I only talk about console display and not graphic session at all.
I suppose it is my fault, I am the one who missed the update of a kernel option, but I do not see which one at all.
If you could help me find it, without having to reboot the server many times, I would greatly appreciate it.
Thanks in advance.
# lspci -vk | grep -A2 "VGA"
00:02.0 VGA compatible controller: Intel Corporation CoffeeLake-S GT2 [UHD Graphics 630] (prog-if 00 [VGA controller])
DeviceName: Onboard - Video
Subsystem: Micro-Star International Co., Ltd. [MSI] Device 7c39
# dmesg -T | egrep -i "vga|graphic|console"
[dim. 15 sept. 14:24:07 2024] Reserving Intel graphics memory at [mem 0x8c000000-0x8fffffff]
[dim. 15 sept. 14:24:07 2024] Console: colour VGA+ 80x25
[dim. 15 sept. 14:24:07 2024] printk: console [tty0] enabled
[dim. 15 sept. 14:24:07 2024] pci 0000:00:02.0: vgaarb: setting as boot VGA device
[dim. 15 sept. 14:24:07 2024] pci 0000:00:02.0: vgaarb: bridge control possible
[dim. 15 sept. 14:24:07 2024] pci 0000:00:02.0: vgaarb: VGA device added: decodes=io+mem,owns=io+mem,locks=none
[dim. 15 sept. 14:24:07 2024] vgaarb: loaded
I realize that dmesg shows something else 2 hours later:
[dim. 15 sept. 16:24:48 2024] irq 16: nobody cared (try booting with the "irqpoll" option)
[dim. 15 sept. 16:24:48 2024] CPU: 1 PID: 0 Comm: swapper/1 Tainted: G O 6.6.47-gentoo #2
[dim. 15 sept. 16:24:48 2024] Hardware name: Micro-Star International Co., Ltd. MS-7C39/B365M PRO-VDH(MS-7C39), BIOS 1.20 01/07/2020
[dim. 15 sept. 16:24:48 2024] Call Trace:
[dim. 15 sept. 16:24:48 2024] <IRQ>
[dim. 15 sept. 16:24:48 2024] dump_stack_lvl+0x32/0x50
[dim. 15 sept. 16:24:48 2024] __report_bad_irq+0x26/0xb0
[dim. 15 sept. 16:24:48 2024] note_interrupt+0x27e/0x2c0
[dim. 15 sept. 16:24:48 2024] handle_irq_event+0x66/0x70
[dim. 15 sept. 16:24:48 2024] handle_fasteoi_irq+0x8c/0x210
[dim. 15 sept. 16:24:48 2024] __common_interrupt+0x5c/0xf0
[dim. 15 sept. 16:24:48 2024] common_interrupt+0x5c/0xd0
[dim. 15 sept. 16:24:48 2024] asm_common_interrupt+0x22/0x40
[dim. 15 sept. 16:24:48 2024] RIP: 0010:handle_softirqs+0x93/0x250
[dim. 15 sept. 16:24:48 2024] Code: 89 6c 24 18 4c 89 7c 24 08 44 88 74 24 07 48 c7 c7 7e 55 e8 81 e8 ad 26 8c 00 65 66 c7 05 cb a9 f2 7e 00 00 fb bd ff ff ff ff <41> 0f bc ec 83 c5 01 0f 84 84 00 00 00 49 c7 c2 c0 60 00 82 44 89
[dim. 15 sept. 16:24:48 2024] RSP: 0018:ffffc9000003cf98 EFLAGS: 00000286
[dim. 15 sept. 16:24:48 2024] RAX: 0000000000000001 RBX: 0000000000000082 RCX: 0000000000000000
[dim. 15 sept. 16:24:48 2024] RDX: 0000000000000000 RSI: ffffffff81e8557e RDI: ffffffff81e753fc
[dim. 15 sept. 16:24:48 2024] RBP: 00000000ffffffff R08: 00000695db59f700 R09: 7fffffffffffffff
[dim. 15 sept. 16:24:48 2024] R10: 00000695dac10082 R11: 0000000000000269 R12: 0000000000000082
[dim. 15 sept. 16:24:48 2024] R13: 000000000000000a R14: 0000000000000000 R15: 00000001000a972c
[dim. 15 sept. 16:24:48 2024] ? handle_softirqs+0x83/0x250
[dim. 15 sept. 16:24:48 2024] irq_exit_rcu+0x6e/0xc0
[dim. 15 sept. 16:24:48 2024] sysvec_apic_timer_interrupt+0x9e/0xc0
[dim. 15 sept. 16:24:48 2024] </IRQ>
[dim. 15 sept. 16:24:48 2024] <TASK>
[dim. 15 sept. 16:24:48 2024] asm_sysvec_apic_timer_interrupt+0x16/0x20
[dim. 15 sept. 16:24:48 2024] RIP: 0010:cpuidle_enter_state+0xa7/0x2c0
[dim. 15 sept. 16:24:48 2024] Code: 45 40 40 0f 84 c2 01 00 00 e8 e5 b1 78 ff e8 90 f6 ff ff 31 ff 49 89 c5 e8 06 23 78 ff 45 84 ff 0f 85 99 01 00 00 fb 45 85 f6 <0f> 88 d7 00 00 00 48 8b 04 24 49 63 ce 4c 89 ea 48 6b f1 68 48 29
[dim. 15 sept. 16:24:48 2024] RSP: 0018:ffffc900000dbe98 EFLAGS: 00000202
[dim. 15 sept. 16:24:48 2024] RAX: ffff88884ec80000 RBX: ffff888100d4f000 RCX: 000000000000001f
[dim. 15 sept. 16:24:48 2024] RDX: 00000695e1bfb795 RSI: ffffffff81e6bd7c RDI: ffffffff81e753eb
[dim. 15 sept. 16:24:48 2024] RBP: 0000000000000001 R08: 0000000000000002 R09: 0000000000000002
[dim. 15 sept. 16:24:48 2024] R10: 0000000000000008 R11: ffff88884eca0344 R12: ffffffff821368a0
[dim. 15 sept. 16:24:48 2024] R13: 00000695e1bfb795 R14: 0000000000000001 R15: 0000000000000000
[dim. 15 sept. 16:24:48 2024] ? cpuidle_enter_state+0x9a/0x2c0
[dim. 15 sept. 16:24:48 2024] cpuidle_enter+0x24/0x40
[dim. 15 sept. 16:24:48 2024] do_idle+0x1a6/0x1f0
[dim. 15 sept. 16:24:48 2024] cpu_startup_entry+0x21/0x30
[dim. 15 sept. 16:24:48 2024] start_secondary+0xf0/0xf0
[dim. 15 sept. 16:24:48 2024] secondary_startup_64_no_verify+0x166/0x16b
[dim. 15 sept. 16:24:48 2024] </TASK>
[dim. 15 sept. 16:24:48 2024] handlers:
[dim. 15 sept. 16:24:48 2024] [<00000000338fd9aa>] i801_isr [i2c_i801]
[dim. 15 sept. 16:24:48 2024] Disabling IRQ #16
Is it possible that this is the cause of my problem?
PS : No systemd, openrc only.
sudo journalctl -b 0lists kernel startup messages that will let you watch it discover the hardware. By varying the-bparameter you can look at other boots (with/without monitor) to see differences. Seesudo journalctl --list-boots./var/log.lessandgrepare of use. Each message starts with a timestamp, the host that issued the log entry, the process name, the PID in[]of the issuer and a colon (:). Everything after the colon is a message from the programmer, intended to help the user understand the program's behavior. Readman loggerfor ONE way of producing log messages.