On Saturday 05 July 2008 21:05:51 Alex Joni wrote: > Very nice work. > We will probably include this asap in TRUNK .. > > I'm not very familiar with Linux GPIO, does the current driver work in > realtime? > Or does it rely on linux stuff which makes it less "realtime"? > > Thanks for the hard work, and giving back to the community.
I did not try it on a real CNC-machine, yet, but I can see proper stepper signals with an oscilloscope at the GPIO outputs. So I'm pretty sure it's fine. There's one little thing that's a little bit strange. I think it comes from my limited understanding of the realtime stuff, however. If the GPIO chip driver does use spin_unlock_irqrestore in the GPIO port write and read handlers, it will cause an exception in the realtime thread. In what context do the RTAPI callbacks run in, exactly? Is there a way to workaround that crash on spin_unlock_irqrestore? I'm not even sure why it crashes, yet. hmm.. However, if I remove all poking with the IRQ flags in the GPIO chip driver, this all works fine. It's also important to say that the GPIO API is not present in 2.6.24, yet, which is unfortunately used for emc2. I tried to port emc2 and rtai to a 2.6.25 kernel, but it turned out to be nontrivial. So I'm currently running this on a 2.6.24 kernel with backported GPIO API from the latest 2.6.26-rc8 release. So I'm fine with putting this into current trunk, however I think it should be disabled by default, as it doesn't compile with a vanilla 2.6.24 kernel. It should work after emc was ported to a 2.6.25 kernel, however. -- Greetings Michael. ------------------------------------------------------------------------- Sponsored by: SourceForge.net Community Choice Awards: VOTE NOW! Studies have shown that voting for your favorite open source project, along with a healthy diet, reduces your potential for chronic lameness and boredom. Vote Now at http://www.sourceforge.net/community/cca08 _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
