答复: [PATCH] x86: move turbo_disabled() out of intel_set_max_freq_ratio

["Li,Rongqing" <lirongqing@baidu.com>]

> Hello,
> 
> the problem is that turbo can be enabled/disabled by the firmware at runtime,
> after the machine has booted.
> 
> This happens for example with the Dell XPS 13, where turbo gets disabled by
> the firmware if the machine is disconnected from AC power and runs on battery.
> The laptop could boot on battery (turbo disabled), then after some time the
> user connects the AC power supply, turbo gets enabled, and with your patch
> we wouldn't know what is the turbo_freq/base_freq ratio to do frequency
> invariance (we skipped reading MSR_TURBO_RATIO_LIMIT at boot because
> turbo was disabled at that timed).
> 
> This behavior was requested by reviewers in this thread:
> https://lore.kernel.org/lkml/1906426.HDqaVa71mF@kreacher/
> and implemented with 918229cdd5ab ("x86/intel_pstate: Handle runtime turbo
> disablement/enablement in frequency invariance").
> 


Thanks for you explanation

Sorry for noise

-Li

> 
> Thanks,
> Giovanni Gherdovich