Re: belkin usb serial converter (mct_u232), break not working

[Paul Fulghum <paulkf@microgate.com>]

Thomas Stewart wrote:

>I've tyred various combinations of ioctl(fd, TCSBRKP, x) and tcsendbreak(fd, 
>x), where x is 2, 5, 10, 20 and 200.
>
>One thing I did notice is that no mater what the value I use, it always 
>finishes very quickly, there does not appear to be any duration.
>
>take porttest.c:
>#include <sys/fcntl.h>
>#include <sys/ioctl.h>
>main(int argc, char ** argv) {
>        int fd = open(argv[1], O_RDWR|O_NOCTTY);
>        ioctl(fd, TCSBRKP, 20);
>        close(fd);
>}
>
>$ time ./porttest /dev/ttyS0
>real    0m2.001s
>user    0m0.001s
>sys     0m0.000s
>
>A standard serial port with a 2 second break (20*100ms), takes as expected 
>just over 2 seconds.
>
>$ time ./porttest /dev/ttyUSB1
>real    0m0.004s
>user    0m0.000s
>sys     0m0.001s
>
>However with the USB converter instead, it takes 5 ms to complete. Much 
>shorter than expected.
>
>Is it a driver issue?
>  
>
Could be.
That test gives me more information.
I will look closer at the code and see if anything pops out.

Thanks,
Paul

--
Paul Fulghum
paulkf@microgate.com