On Wed, 2014-12-03 at 08:09 +0100, Sebastian Huber wrote: > Hello Nick, > > to disable TCR[ARE] is not the right fix. You have to check the > TSR[DIS] register in the nanoseconds extension. See for example > lpc-clock-config.c for an example.
Hi Sebastian, Thanks for your help, 'fraid I need to lean on you a little more... I don't understand how the proposed solution (or that in lpc-clock-config.c) can work properly in the case where the nanoseconds extension could be queried multiple times with an interrupt lock held (which I believe disables interrupts), preventing the tick from being incremented, as I believe happens in spnsext01. lpc-clock-config.c's lpc_clock_nanoseconds_since_last_tick(), if I'm understanding it correctly, says "Ah, there's an interrupt pending, so we need to add another tick period to our current timer value". Cool bananas. But what if it's called again with the same interrupt still pending? The timer counter may have wrapped again and we could return an earlier time. ...Couldn't we? What am I missing? Cheers :-) -- Nick Withers Embedded Systems Programmer Department of Nuclear Physics, Research School of Physics and Engineering The Australian National University (CRICOS: 00120C) _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel
