Chris Morley wrote: > Gentlemen: > I was reading the thread with Sebastian and John about calls in drivers And > I have a question along those lines: > When I made the opto ac5 driver I followed the frame work of the original > Mesa driver and it had separate calls for reading and writing i/o. > Now after I've thought about it, I think it would be faster to do both at the > same time (I don't have to decode the mask bits four times,only twice) > Is there any reason to have separate calls for reading and writing to an I/O > port? > > Thanks > Chris Morley
Yes - usually the desired flow is: 1) read inputs 2) do some processing using that data 3) write outputs with the results If you read and write at the same time, you wind up with something like: 1) write the outputs that were computed in the last run of the thread 2) while reading new data 3) then compute new output 4) that you do nothing with until the next run of the thread Regards, John Kasunich ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
