On 17 February 2014 13:49, Srivatsa S. Bhat <srivatsa.bhat@xxxxxxxxxxxxxxxxxx> wrote: > Quick question: Looking at cpufreq_update_policy() and cpufreq_out_of_sync(), > I understand that if the cpufreq subsystem's notion of the current frequency > does not match with the actual frequency of the CPU, it tries to adjust and > notify everyone that the current frequency is so-and-so, as read from the > hardware. Instead, why can't we simply set the frequency to the value that > we _want_ it to be at? I mean, if cpufreq subsystem thinks it is X KHz and > the actual frequency is Y KHz, we can as well fix the anomaly by setting the > frequency immediately to X KHz right? > > The reason I ask this is that, if we follow this approach, then we can avoid > ambiguities in dealing with the out-of-sync situation. That is, it becomes > very straightforward to decide _what_ to do, when we detect scenarios where > the frequency goes out of sync. Hmm, it is just about doing all that stuff in a single line, like: __cpufreq_driver_target(...) ?? There are few problems here: - If we simply call above routine with X, then it will simply return as X == policy->cur. And I don't want to hack this code in a bad way now :) - So, probably the way it is implemented is right, as we do that the most efficient way. We just broadcast the new freq in case there is a difference otherwise nothing. -- To unsubscribe from this list: send the line "unsubscribe cpufreq" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
