On Mon, Aug 31, 2015 at 7:33 PM, vichy <vichy.kuo@xxxxxxxxx> wrote: > hi all: > My platform is like below: > 1. single core Cortex A9 > 2. use global timer for system timer > > after I porting cpu frequency driver based on snow ball, the cpu > frequency did change as I expected. > But the system time is incorrect( since pherial clk is got from cpu frequency) > > for example: > a) cpu 1G (pherial clk = 250M) --> sleep 1 sec (OK) > b) cpu 500M (pherial clk = 125M) --> sleep 1 sec (will be measured as 2 sec) > > I try to call below 2 functions to change the frequency of clocksource > and clockevent, but the above b) sleep time is still incorrect when > cpu runs in 500Mhz. > clockevents_update_freq(this_cpu_ptr(gt_evt), gt_clk_rate); > __clocksource_updatefreq_hz(>_clocksource, gt_clk_rate); > > in Arm cortex A9 single core system with Global timer as system timer, > is there any kernel api to change system timer period when cpu/pherial > frequency change? > > appreciate your kind help in advance, The list cpufreq@xxxxxxxxxxxxxxx is the wrong list for posting cpufreq queries as we have moved to Linux PM list <linux-pm@xxxxxxxxxxxxxxx> list now. Try unsetting CPUFREQ_CONST_LOOPS flag in your driver, if you have it set. -- 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
