A seemingly late patch for the Intel Idle (intel_idle) Linux kernel driver enables support for upcoming Xeon 6 Granite Rapids processors.

The intel_idle driver is used for CPU idle time management and helping to ensure the CPU cores when idle can reach their lower-power states. A patch posted to the Linux kernel mailing list on Tuesday extend the Intel Idle driver for upcoming [1]Granite Rapids processors.

[2]The patch confirms Granite Rapids' C-States and notes:

"Add Granite Rapids Xeon C-states, which are C1, C1E, C6, and C6P.

Comparing to previous Xeon Generations (e.g., Emerald Rapids), C6 requests end up only in core C6 state, and no package C-state happens (even if all cores are in core C6). C6P requests also end up in core C6, but if all cores are idle, the SoC enters the package C6 state."

With the launch of Granite Rapids becoming quite close (by the end of this quarter...) and much of the rest of the Granite Rapids Linux enablement having been done many months ago, it's a bit surprising this Intel Idle driver support is coming rather at the last minute. This will likely land for the Linux v6.12 kernel unless it's ushered in as a "fix" for the ongoing v6.11 cycle.



[1] https://www.phoronix.com/search/Granite+Rapids

[2] https://lore.kernel.org/linux-pm/20240806160310.3719205-1-artem.bityutskiy@linux.intel.com/