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Check the TS kernel if the patches have any modifications that are interfering with timing.
RT kernel makes the timing functions much more predictable. Compile the kernel with 1000 hz if possible. I haven't touched the TS kernel yet , but worked to port the kernel 3.4 on a Freescale board. Unpredictability can come from bad drivers , heavy network load etc. From: MrRealityCheck <> To: Sent: Monday, November 26, 2012 9:01 PM Subject: [ts-7000] Re: Inconsistent usleep and ITIMER_REAL I thought about that but that it seems like I'd not really be solving the problem. I suppose I have nothing to lose but a lot of time.
FYI, the wiki is here: https://rt.wiki.kernel.org/index.php/Main_Page I just find it worrisome that core timing functions are suddenly that unpredictable. If I knew how these functions tied into the hardware, I might be able to determine if I've screwed something up which is entirely possible given that I've been taking the ynezz/mcrapet code and adding 7350-specific addresses/features. I'm tempted to go brute force and try one version after another until it breaks. --- In , harry olar <> wrote: > > You could try the rt patch > http://www.kernel.org/pub/linux/kernel/projects/rt/ > > > > > ________________________________ > From: MrRealityCheck <> > To: > Sent: Saturday, November 24, 2012 9:00 PM > Subject: [ts-7000] Inconsistent usleep and ITIMER_REAL > > > Â > So, I've been using a 3.0.4 kernel from ynezz/mcrapet tweaked for a 7350 for a while now. I also set the kernel HZ to 1000 so I could get close to millisecond timing. That's been working fine. usleep is pretty consistent. Also, ITIMER_REAL has been pretty consistent. I've used this to check the kernel frequency with some code I found via google. The Hz value hovers around 980 Hz. Plus or minus less than 5%. > > Now, I wanted to upgrade the kernel. I started with stock 3.5.7 and attempted to apply the 7350 specific and TS board specific stuff e.g. the SD card drivers. When I build the kernel however, my kernel frequency becomes really unpredictable varying from as little as 450 Hz to as much as 950 Hz. Both usleep and ITIMER_REAL are affected. I can't figure out what I'm doing wrong or if the kernel code itself is to blame. I've tried a 3.6.6 kernel and I've tried ynezz's 3.3.8 kernel as well. It's possible I missed something because the ynezz code doesn't have 7350-specific stuff. > > Any ideas? I've posted something about this to Linuxquestions but have yet to get a response. > __._,_.___
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