[First bug report, apologies if I break etiquette, pointers appreciated.] Laptop crashes when booting on AC power. The laptop is on Gentoo; upgrading from 5.15.88 to 6.1.12, the kernel panics before reaching early userspace. I find no other report like this on the Gentoo, arch, mint, or Ubuntu forums, on kernel.org, or out of duckduckgo. This is a regression (because, you know, the kernel used to boot) but so far it's only me, and only on my 16-year old laptop. Also, I have a workaround. Image of the panic screen at https://www.panix.com/~pa/linux-6.1.12-crash/boot-failure.jpg . Seeing acpi_ac_notify() near the top of the traceback, I tried booting on battery power. Works fine. The panic occurs only when booting on AC power, whether or not a battery is present. Sometimes, rarely, it boots fine even on AC, but that is the exception not the rule. Based on comments in drivers/acpi/ac.c I tried a trivial patch, --- drivers/acpi/ac.c.orig 2022-12-11 17:15:18.000000000 -0500 +++ drivers/acpi/ac.c 2023-02-19 17:38:06.958733031 -0500 @@ -47,7 +47,7 @@ static int acpi_ac_resume(struct device #endif static SIMPLE_DEV_PM_OPS(acpi_ac_pm, NULL, acpi_ac_resume); -static int ac_sleep_before_get_state_ms; +static int ac_sleep_before_get_state_ms = 1000; static int ac_only; static struct acpi_driver acpi_ac_driver = { and it works. This is probably not the right fix but it will be my workaround for the time being. Problem is still present in 6.3-rc1 . Bisecting, the first bad commit is d6fb6ee1820c . The starting config (from 5.15.88) is at https://www.panix.com/~pa/linux-6.1.12-crash/config-base . The test is make olddefconfig, make bzImage, then kexec the bzImage with an initramfs to see if it reaches the rescueshell prompt. Has to succeed three times to be declared good. In case I forgot something, here is my post on the Gentoo forums: https://forums.gentoo.org/viewtopic-t-1161834-highlight-.html #regzbot introduced d6fb6ee1820c Also in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=217152
