The Linux Kernel Getting Fixed Up For Booting On Some Intel Systems - No "8254"
There have been Linux reports of problems pertaining to "8254 Clock Gating" going back a while but more so recently. This problem is some newer Intel Skylake~Apollolake derived systems particularly with Intel SoCs where certain systems ship with the 8254 PIT to be gated via a special register and up until now that has caused Linux to fail to boot.
With the PIT gating by default, Linux would fail to boot with a kernel panic over "IO-APIC + timer doesn't work!" But as this panic would happen before the frame-buffer is even setup, it would be hard for users to diagnose and workaround. There has been a workaround often of toggling the "8254 Clock Gating" option within the affected systems' BIOS. But now there's a kernel patch pending to make Linux happy in the no-8254 configuration.
The patch contains additional details for those interested. That fix is currently queuing in the x86/apic tree. Given an uptick in recent reports around "8254 clock gating" woes appearing in Google search results, good to see Linux getting fixed for these Intel systems.
With the PIT gating by default, Linux would fail to boot with a kernel panic over "IO-APIC + timer doesn't work!" But as this panic would happen before the frame-buffer is even setup, it would be hard for users to diagnose and workaround. There has been a workaround often of toggling the "8254 Clock Gating" option within the affected systems' BIOS. But now there's a kernel patch pending to make Linux happy in the no-8254 configuration.
The patch contains additional details for those interested. That fix is currently queuing in the x86/apic tree. Given an uptick in recent reports around "8254 clock gating" woes appearing in Google search results, good to see Linux getting fixed for these Intel systems.
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