> From: Dave Milter [mailto:[email protected]] > > you think that settting flag on arm9 is atomic thing? > > I look at code atomic in linux kernel, in case of arm9 (armv5 core) it > disable interrupts set flag and then enable interrupts.
Unconditionally setting a byte flag is certainly atomic, on any CPU. Incrementing a flag isn't, nor is testing it and setting, which means that these things can only be done by something that isn't interruptible. If the application stores 1 in a byte, the interrupt handler can safely test and set it back to 0 it at the beginning. This should work even in an SMP environment, because only one CPU will run the interrupt handler at a time. Whether this solves the original problem, I have no idea. -- Ciao, Paul D. DeRocco Paul mailto:[email protected] -- Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
