A fix was merged to the Linux 6.14 kernel on Friday — and also for back-porting to existing Linux stable kernels over the coming days — for fixing an annoying problem with Intel Core 2 processors. The problem, which was introduced to the Linux kernel back in 2019, could lead to system stalls and boot delays for those still using Intel Core 2 CPUs with modern distributions.
It looks like not many are still using Intel Core 2 CPUs with Linux or if they are just sticking to older kernels / distributions. A fix was merged yesterday for a Linux kernel bug introduced in late 2019 to the Intel Idle driver. A few months back a user reported a Linux kernel regression that when upgrading from Debian Bullseye to Debian Bookworm, he found his system getting stuck in the boot process for more than 60 seconds.
The issue comes down to the modern Intel Idle driver not implementing a workaround for Intel Core 2 generation processors where the time stamp counter (TSC) stops in C2 and deeper C-states. In turn this causes stalls and boot delays. The ACPI driver had marked the TSC unstable when noting this situation while only now the Intel Idle driver is making this workaround.
So this fix is merged to Linux 6.14 Git ahead of Linux 6.14-rc5 on Sunday to fix this stalled boot / stuck behavior on old Intel Core 2 systems. The workaround will also be back-ported to stable series in the coming days for those still relying on Intel Core 2 hardware.
