On Fri, Nov 30, 2001 at 12:03:41AM -0500, erlichr wrote: > I've been tring to get the knack of the posix API.
Still trying. Had a pretty good grasp of the old v1 API. Happy to say I'm making progress though. > The attached code is influenced by "Frank" example. The idea is to make a four >channel pwm generator to drive motors hung off the port. The code has evolved a bit since then, and getting an oscilliscope on the outputs helped in debugging timing issues. This is actually the first step in an attempt to create a closed loop, PID filter servo motor controller. I'm currently gathering parts for a shaft encoder interface (looking at a pair of LSI LS7266). > Testing with rtl_printk showed the fifos processed writes correctly and the correct >bit patterns were being generated and written to the printer port. Yup, the rtl_printk's were fine, and it was a stretch to say the patterns were being written to the printer port; I had the arguments in the rtl_outb reversed. So, the LSB of the printer port address got written to addresses created by correctly generated bit pattern. D'oh. > Where this all seems to fall down is after addition of the code to suspend a >thread. Sporadic hard lockups when writing from user space to the fifos (usually 3, >but not allways) and sometimes during rmmod. Yea, this makes sense now. > Again, the posix API is still new so I may not be grokking where and how to use >mutex locks or thread suspention/wake_up. Still applies, but I no longer have to deal with nasty fscks increasing my test/debug cycle time. BTW, is there a patch set for a more recent kernel, I'd really like to be using the Archangeli VM, as well as ext3 or preferably xfs as a filesystem (see above). > There is no contention for the io space of the printer port, parport_pc and parport >modules are unloaded. Yea, 'cause I'm wasn't actually writing to the printer port ;) > Any help, advice or research direction would be greatly appreciated. Thanks to those who replied. BTW, is there a problem with the list? I'm not getting traffic from it, or is my subscription messed up. -R. -- GPG-fingerprint: 6CE9 8B6E 8089 FECC 4AA6 9CC9 F2B3 70A6 E98A 8B77
msg02130/pgp00000.pgp
Description: PGP signature
