On Friday 19 August 2011 16:10:43 Gordan Bobic wrote: > On Fri, 19 Aug 2011 15:55:57 +0200, Marc Dietrich <[email protected]> wrote: > > Am Freitag 19 August 2011, 11:18:31 schrieb Gordan Bobic: > >> As some of you may have already heard on the IRC channel, I had my > >> AC100 suddenly become very unstable under load. When doing big > >> compile > >> [...] > >> My gut feeling at the moment is that the RAM could be over-timed so > >> I'm going to try modifying the kernel code to relax the RAM timings by > >> a notch. > > > > we are not touching RAM timings so far on kernel 2.6.38. It may be > > possible that the original kernels does so. > > Well, my plan was to up the timings in > arch/arm/mach-tegra/board-paz00-memory.c. Can you confirm whether the > values there are in units of clock cycles? Or is it ns? Also which line > corresponds to CAS? I can see RAS, RC, RCD, RRD, RFC, but can't see a > value for CAS, which is, at least in theory, the most imporant one.
AFAIK, they are in cycles, but as I said, these values are not used now (see the ifdef 0 at the end of the file). The reason is that I don't have the values for 166 MHz on Micron and the Hynix tables caused instabilities. So they are just there as a "reminder". But of course, you can remove the ifdef and try yourself. > > [...] > > It could also be related to power supply. What we do is modifing the > > voltage > > supplies for serveral power sources. I had the feeling, that Toshiba > > undervoltaged some CPU supplies in order to save energy (compared to > > other > > boards). So I increased SM1 from 1V to 1.2V which may have been > > wrong. > > How did you do this? check board-paz00-power.c > > It would be nice if you could test a .32 based kernel and see if it > > also happens there. Also you could try your new model. > > I haven't tried 2.6.32 because I couldn't find one at the time, but I > tried the old 2.6.29 and 2.6.38, and the instability on my old AC100 was > the same. Haven't tried it on the new one yet. Do you think 2.6.32 could > be behaving differently to both of those? If so, why? Where can I get > the Tegra-patched 2.6.32 kernel? gitorious.org/ac100? (on the front page) Marc _______________________________________________ Mailing list: https://launchpad.net/~ac100 Post to : [email protected] Unsubscribe : https://launchpad.net/~ac100 More help : https://help.launchpad.net/ListHelp
