On Fri, May 15, 2015 at 12:36:10PM +0200, Mason wrote: > On 15/05/2015 11:51, Russell King - ARM Linux wrote: > > > As you don't say which kernel version you're using, > > Sorry about that, I thought the patch-generating command > I posted conveyed the information. > > $ git diff v3.14.41 HEAD >tango.patch && xz tango.patch > > I'm using the 3.14.y branch from linux-stable. So you're using a kernel over a year old... > > for all we know, you might be using a version which omits some fixes > > in this area, such as this one which you really must have if your > > timer is operating in period mode: > > > > fe79a9ba1196 clockevents: Adjust timer interval when frequency changes > > Hmmm, according to git log, this patch was accepted during > the 3.14-rc2 merge window. Why didn't it make it for 3.14? No it wasn't: $ git describe --contains fe79a9ba1196 v3.15-rc1~123^2~12 It was merged during the merge window immediately preceding v3.15-rc1. > By any chance, is there a patch that would allow the platform > to get high-resolution timers when using smp_twd? I think you'll have to do the research for that yourself... what I can say is that TWD is capable of one-shot mode, and is capable of running as a high-res timer: Per CPU device: 0 Clock Event Device: local_timer max_delta_ns: 21691754031 min_delta_ns: 1000 mult: 425201762 shift: 31 mode: 3 <== CLOCK_EVT_MODE_ONESHOT next_event: 595603944000000 nsecs set_next_event: twd_set_next_event set_mode: twd_set_mode event_handler: hrtimer_interrupt <== indicates that it's switched to high-res mode retries: 0 -- FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up according to speedtest.net. -- 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
