Re: schedule_timeout sleeps too long after dividing CPU frequency
Viresh Kumar <[email protected]> Thu, 14 May 2015 17:24:56 +0530
| Newsgroups | org.kernel.vger.cpufreq,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-pm |
|---|---|
| Message-ID | <20150514115456.GB23999@linux> |
On 14-05-15, 13:22, Mason wrote: > I didn't /literally/ take a stop-watch to verify it was EXACTLY > 9 seconds, but I was staring at the prompt, and it /felt/ like > 9 seconds. And the 54 second case felt like a minute. :) > I'm using a 27 MHz crystal as clocksource. This is independent > of the CPU frequency. However, I'm using the ARM TWD as the > system's clockevent source, and the TWD's clock is tied to > the CPU clock (PERIPHCLK = CPUCLK / 2 on this SoC). The only (very straight forward) problem is that we aren't propagating the freq update to clockevents core and you need to debug a bit there. Also I wanted to see the source of your print message: [ 19.650454] NEW RATE=9250000 [ 19.653644] NEW RATE=9250000 What's this rate ? Old/new ? Because you are atleast printing the old rate here, and the function by default gets the new rate. > I'm wondering if there's another standard clockevent source > I could try (it would be great if it supported high-resolution > timers). I hope you have some platform general-purpose-timers. -- viresh