Hi Sven, The device manufacturer has made some kernel modifications to support their board, and those are specific to 2.6.19. (In fact, they're specific to 2.6.19.2 OpenWRT patches). There's also a large driver which is appropriate for an old kernel but would need some re-engineering to deal with API changes in 2.6.20 or 2.6.21, I believe. So, if getting high-resolution timing with this kernel is going to be a nightmare, I can try taking on a newer kernel. But it'll be an ordeal. -Eric Thus spake Sven-Thorsten Dietrich (thebigcorporation@xxxxxxxxx): > On Tue, 2010-06-08 at 12:17 -0600, Eric W Anderson wrote: > > Hello All, > > Hi Eric, > > 2.6.19 is very very old. > > What is preventing you from a Kernel upgrade? > > Sven > > > > > > I can't figure out (or haven't figured out) how to get actual high-resolution > > timers on the above platform. I'm kind of stuck with 2.6.19, unfortunately. > > I've applied the -rt patch to stock 2.6.19, merged in some random patches to > > support my hardware, and gotten it to boot. But, here's what confuses me: I > > have the hrtimer API, but my actual clock resolution is still shown as 10ms. > > > > root@patty:/# cat /proc/timer_list > > Timer List Version: v0.1 > > HRTIMER_MAX_CLOCK_BASES: 2 > > now at 2766685920305 nsecs > > > > cpu: 0 > > clock 0: > > .index: 0 > > .resolution: 10000000 nsecs > > .get_time: ktime_get_real > > active timers: > > clock 1: > > .index: 1 > > .resolution: 10000000 nsecs > > .get_time: ktime_get > > active timers: > > #0: <c4615ec8>, hrtimer_wakeup > > # expires at 2766802147358 nsecs [in 116227053 nsecs] > > #1: <c4615ec8>, it_real_fn > > # expires at 2767494816966 nsecs [in 808896661 nsecs] > > #2: <c4615ec8>, it_real_fn > > # expires at 3642163204498 nsecs [in 875477284193 nsecs] > > #3: <c4615ec8>, it_real_fn > > # expires at 3643403169278 nsecs [in 876717248973 nsecs] > > > > Additionally, I don't see CONFIG_HIGH_RES_TIMERS anywhere in my kernel > > menuconfig. I've added a patch from Kevin Hilman and Milan Svoboda > > (http://lkml.indiana.edu/hypermail/linux/kernel/0607.1/2343.html) which > > purports to enable a high-resolution clock event source for this board, but > > that doesn't seem to change anything. > > > > I think I don't properly understand the preempt_rt / hrtimers / > > board-specific-bits ecosystem here. What are the bits and pieces I need in > > order to have high-resolution timers on this platform? > > > > Many, many thanks, > > Eric Anderson > > > > > > -- Eric W. Anderson University of Colorado eric.anderson@xxxxxxxxxxxx Dept. of Computer Science phone: +1-720-984-8864 Systems Research Lab - ECCR 1B54 PGP key fingerprints: personal: 1BD4 CFCE 8B59 8D6E EA3E EBD5 4DC9 3E61 656C 462B academic: D3C5 D6FF EDED 9F1F C36D 53A3 74B7 53A6 3C74 5F12
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