On Saturday 05 July 2008 21:05:51 Alex Joni wrote: > Or does it rely on linux stuff which makes it less "realtime"?
I forgot to answer that question. Yes, it calles into the linux GPIO API. So this makes it "less realtime". However that depends on the device that provides the GPIO. There are devices where the gpio_set_value and gpio_get_value are inlined and result in only a few CPU instructions. So in that case it won't hurt realtime. In my case it will result in a function call and a spin_lock. However that spin_lock will never be contented in practice, so I think it will not hurt realtime here, too. There are other GPIO chip drivers that use workqueues and process context for setting the pins. These are completely unusable for this stuff, of course. So the answer to the question whether this is a realtime thing is: It depends on the hardware and the driver that provide the GPIOs. -- 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 [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
