- From: L.C. Karssen <l.c.karssen_at_phys.uu.nl>
- Date: Wed, 23 May 2007 14:35:44 +0200
After getting rid of the syscalls during hard RT as described below, I
found that the DIO lines are no longer being flipped. Only the analog
out works.
When I replaced the call to comedi_dio_bitfield() with 8 calls to
comedi_dio_write() (one for each DIO channel) it works again.
Unfortunately this takes too much time. I set a period of 20us, but when
I record the time using rt_get_time_ns to check the time difference
between to successive iterations of my for-loop I see that about once in
every three iterations the time difference is 40us, indicating that the
execution took more that one period.
Just to emphasise that my usage of comedi_dio_bitfield() is in principle
OK: Using comedi_dio_bitfield() in my code works when including
comedilib.h instead of rtai_comedi.h (but this results in syscalls being
made).
So, can anybody tell me if using comedi_dio_bitfield() in hard RT works
for him/her? In RTAILabs rtai_comedi_dioout.c I see that only
comedi_dio_write() is used. I also noticed that rtai_comedi.h doesn't
have a wrapper for the (new) comedi_dio_bitfield2() function (which is
supposed to supersede the comedi_dio_bitfield() function if I'm not
mistaken).
Thanks,
Lennart.
On Tue, 2007-05-22 at 14:09 +0000, L.C. Karssen wrote:
> I think I solved/worked around the problem. I don't include comedilib.h
> anymore and I changed the comedi_t pointer for a comedi device to a void
> pointer (as expected by rtai_comedi.h). Furthermore I removed all
> references to the comedi_range struct and the calls to
> comedi_get_range() and comedi_perror(). These functions are not defined
> in rtai_comedi.h (but are defined in comedilib.h, which I no lnger
> include).
> This removes any errors about either missing or double definitions.
> No more syscalls are added to /proc/rtai/scheduler. Everything seems to
> work now.
>
> It's probably not the nicest solution, but it works. If somebody has a
> better solution, I'll be glad to hear it.
>
>
> Lennart.
>
> On Mon, 2007-05-21 at 19:09 +0200, L.C. Karssen wrote:
> > On Mon, 2007-05-21 at 16:30 +0000, L.C. Karssen wrote:
> > > On Mon, 2007-05-21 at 19:52 +0200, Paolo Mantegazza wrote:
> > > > L.C. Karssen wrote:
> > > > > On Mon, 2007-05-21 at 09:42 +0000, L.C. Karssen wrote:
> > > > >
> > > > >>On Sun, 2007-05-13 at 23:37 +0200, Paolo Mantegazza wrote:
> > > > >>
> > > > >>>L.C. Karssen writes:
> > > > >>>
> > > > >>>
> > > Furthermore, I looked at rtai_comedi_dioout.c from RTAILab and found
> > > that it includes rtai_comedi.h. I have the following RTAI and comedi
> > > related includes:
> > > #include "/usr/local/include/comedilib.h"
> > > #include <rtai_lxrt.h>
> > >
> > > I included rtai_comedi.h but that resulted in a lot of errors because of
> > > overshadowed definitions (because of comedilib.h).
> > An example of such an error:
> >
> > In file included from daqwrite.c:25:
> > /usr/realtime/include/rtai_comedi.h:123: error: conflicting types for
> > 'comedi_open'
> > /usr/local/include/comedilib.h:68: error: previous declaration of
> > 'comedi_open' was here
> >
> >
> > In comedilib.h:68:
> > comedi_t *comedi_open(const char *fn);
> >
> > In rtai_comedi.h:123:
> > RTAI_PROTO(void *, comedi_open,(const char *filename))
> > {
> > char lfilename[COMEDI_NAMELEN];
> > struct { char *minor; } arg = { lfilename };
> > strncpy(lfilename, filename, COMEDI_NAMELEN - 1);
> > return rtai_lxrt(FUN_COMEDI_LXRT_INDX, COMEDI_LXRT_SIZARG,
> > _KCOMEDI_OPEN, &arg).v[LOW];
> > }
> >
> >
> > > When only including
> > > rtai_comedi.h I get a lot of syntax errors. I'm going to check why that
> > > happens.
> >
> > When not including /usr/local/comedilib.h I get errors because of
> > missing definitions of e.g. comedi_t, comedi_range and comedi_dev. The
> > typedefs of these are in comedilib.h.
> > I need those to initialise my comedi device, as in the following code
> > for example:
> > comedi_t *comedi_dev;
> > comedi_dev = comedi_open(comedi_devname);
> >
> >
> > Lennart
> >
> > >
> > > Thanks,
> > >
> > > Lennart
> > > >
> > > > Paolo
> > > >
> > > > >
> > > > >
> > > > >>Any help is appreciated!
> > > > >>
> > > > >>
> > > > >>Lennart.
> > > > >>
> > > > >>
> > > > >>int do_comedi(struct data_struct *options)
> > > > >>{
> > > > >> comedi_t *comedi_dev = options->device;
> > > > >> unsigned int ao_subdev = options->AO_subdevice; // Analog Output
> > > > >> unsigned int dio_subdev = options-> DIO_subdevice; // Digital IO
> > > > >> int range=0; // AO has only one range: 10V -> -10V
> > > > >> comedi_insn insn;
> > > > >> lsampl_t data;
> > > > >> unsigned int dio_bits;
> > > > >> int aref = AREF_GROUND;
> > > > >> unsigned int dio_mask = 0xFFFFFFFF; // Tells which DIO bits are to
> > > > >>be flipped (all).
> > > > >>
> > > > >> int period;
> > > > >> struct bits *data_arr = options->bitsarr;
> > > > >>
> > > > >> RT_TASK* task;
> > > > >> int priority=0;
> > > > >> int stack_size=4096;
> > > > >> int msg_size=0;
> > > > >>
> > > > >> int i;
> > > > >>
> > > > >> /* Prepare the AO instruction as much as possible. Later, in real
> > > > >>time
> > > > >> * we'll only fill in the data sample. */
> > > > >> insn.insn = INSN_WRITE;
> > > > >> insn.n = 1;
> > > > >> insn.subdev = ao_subdev;
> > > > >>
> > > > >> /* A better scheduler than linux' one */
> > > > >> struct sched_param mysched;
> > > > >>
> > > > >> /* We don't want to be swapped out the mem */
> > > > >> mlockall (MCL_CURRENT | MCL_FUTURE);
> > > > >> /* Allow nonroot users hard realtime access */
> > > > >> rt_allow_nonroot_hrt();
> > > > >>
> > > > >> /* Initialise Scheduler as SCHED_FIFO. Greatly improves scheduler!
> > > > >>*/
> > > > >> mysched.sched_priority = sched_get_priority_max(SCHED_FIFO) - 1;
> > > > >> if( sched_setscheduler( 0, SCHED_FIFO, &mysched ) == -1 )
> > > > >> {
> > > > >> fprintf(stderr, "Error in setting the Scheduler!\n");
> > > > >> exit(1);
> > > > >> }
> > > > >>
> > > > >> /* Register this thread as a RT task. As long as it's
> > > > >> not switched to hard_real_time, it's still a normal process and
> > > > >> can do all normal things */
> > > > >> task = rt_task_init(nam2num("do_comedi"), priority, stack_size,
> > > > >>msg_size);
> > > > >>
> > > > >> // Set mode to periodic. Other option is 'oneshot'
> > > > >> rt_set_periodic_mode();
> > > > >> period = (int) nano2count((RTIME)options->period*1000);
> > > > >>
> > > > >> start_rt_timer(period);
> > > > >>
> > > > >> // Switch to hard realtime mode
> > > > >> rt_make_hard_real_time();
> > > > >>
> > > > >> // Start scheduler
> > > > >> rt_task_make_periodic(task, rt_get_time() + period, period);
> > > > >>
> > > > >>
> > > > >> for (i=0; i<options->n_rows; i++)
> > > > >> {
> > > > >>
> > > > >> /* Prepare and write digital data. */
> > > > >> dio_bits = data_arr[i].DIO;
> > > > >> comedi_dio_bitfield(comedi_dev, dio_subdev, dio_mask, &dio_bits);
> > > > >>
> > > > >> /* Prepare and write AO data */
> > > > >> data = data_arr[i].AO0;
> > > > >> insn.data = &data;
> > > > >> insn.chanspec = CR_PACK(0, range, aref);
> > > > >> if(comedi_do_insn(comedi_dev, &insn)<0)
> > > > >> {
> > > > >> comedi_perror("/dev/comedi0");
> > > > >> exit(1);
> > > > >> }
> > > > >>
> > > > >> data = data_arr[i].AO1;
> > > > >> insn.data = &data;
> > > > >> insn.chanspec = CR_PACK(1, range, aref);
> > > > >> if(comedi_do_insn(comedi_dev, &insn)<0)
> > > > >> {
> > > > >> comedi_perror("/dev/comedi0");
> > > > >> exit(1);
> > > > >> }
> > > > >> rt_task_wait_period();
> > > > >> }
> > > > >>
> > > > >> rt_make_soft_real_time();
> > > > >>
> > > > >>#ifdef DEBUG
> > > > >> printf("We're back in soft realtime.\n");
> > > > >>#endif
> > > > >>
> > > > >> // Stop timer
> > > > >> stop_rt_timer();
> > > > >>
> > > > >> // Unregister RT task
> > > > >> rt_task_delete(task);
> > > > >>
> > > > >> // Unlock mem
> > > > >> munlockall();
> > > > >>
> > > > >> return 0;
> > > > >>}
> > > > >>
> > > > >>
> > > > >>
> > > > >>>Paolo.
> > > > >>>
> > > > >>>
> > > > >>>>Lennart.
> > > > >>>>--
> > > > >>>>*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
> > > > >>>>L.C. Karssen
> > > > >>>>Department of Physics and Astronomy
> > > > >>>>Faculty of Science
> > > > >>>>Utrecht University
> > > > >>>>Princetonplein 1
> > > > >>>>3584 CC Utrecht
> > > > >>>>The Netherlands
> > > > >>>>
> > > > >>>>tel.: +31 (0)30-253-2208
> > > > >>>>fax.: +31 (0)30-253-7468
> > > > >>>>e-mail: L.C.Karssen_at_phys.uu.nl
> > > > >>>>www: http://www1.phys.uu.nl/wwwaoud
> > > > >>>>-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-
> > > > >>>>
> > > > >>>>
> > > > >>>>_______________________________________________
> > > > >>>>RTAI mailing list
> > > > >>>>RTAI_at_rtai.org
> > > > >>>>https://mail.rtai.org/cgi-bin/mailman/listinfo/rtai
> > > > >>>
> > > > >>>
> > > >
--
*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
L.C. Karssen
Department of Physics and Astronomy
Faculty of Science
Utrecht University
Princetonplein 1
3584 CC Utrecht
The Netherlands
tel.: +31 (0)30-253-2208
fax.: +31 (0)30-253-7468
e-mail: L.C.Karssen_at_phys.uu.nl
www: http://www1.phys.uu.nl/wwwaoud
-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-
Received on 2007-05-23Z11:35:44