On Wed, Sep 22 2021 at 22:27, Rafael J. Wysocki wrote:
On Tue, Sep 21, 2021 at 10:18 PM Thomas Gleixner tglx@linutronix.de wrote:
On Tue, Sep 21 2021 at 20:05, Rafael J. Wysocki wrote:
On 9/19/2021 2:14 AM, Thomas Gleixner wrote:
What's the proper way to figure out whether PC10 is supported?
I can't say without research. I think it'd be sufficient to check if C10 is supported, because asking for it is the only way to get PC10.
Do we have a common function for that or do I need to implement the gazillionst CPUID query for that?
intel_idle has intel_idle_verify_cstate() that works on MWAIT substates from CPUID. It looks like this could be reused.
Not to me. That's some cpuidle/intel_idle specific check which depends on cpuidle_state_table being set up which is not available during early boot.
The question I was asking whether we have a central place where we can retrieve such information w/o invoking CPUID over and over again and applying voodoo checks on it.
Obviously we don't, which sucks.
Thanks,
tglx