Re: problem with select() - 2.4.5
Thomas Speck wrote: > > tio.c_cflag = baud | CLOCAL; How about adding CREAD? Ciao, ET. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: problem with select() - 2.4.5
On Fri, 22 Jun 2001, Thomas Speck wrote:
>
> Hi !
> I have a problem with reading from a serial port using select() under
> 2.4.5. What I am doing is basically the following:
>
> fd_set readfds;
> struct timeval timeout;
> int s;
>
> serialfd = open("/dev/ttyS0", O_RDWR );
>
> init_serial(B9600);
>
> timeout.tv_sec = 2; /* ! */
> timeout.tv_usec = 0;
> FD_ZERO();
> FD_SET(serialfd,);
>
> s=select(serialfd+1, , NULL, NULL, );
> ...
>
> But s is always equal to 0 even when I am sure there are data to read.
> If I use
>
> s=select(serialfd+1, NULL, , NULL, );
>
> (with the corresponding initialisation of writefds) it returns s=1 and I
> can write to the serial port. I can see that since the lights of the modem
> are flashing.
> I noticed that behavior since I tried to send some "ATZ" with the
> write-function but I never got the "OK" back.
>
> However, the same programme works under 2.2.19.
Probably I should have given the init_serial() as well; So here it is:
(it is basically the one from the serial-programming-howto)
int init_serial(tcflag_t baud)
{
struct termios tio;
tcgetattr(serialfd,);
tio.c_cflag = baud | CLOCAL;
tio.c_iflag = IGNPAR;
tio.c_oflag = 0;
tio.c_lflag = 0;
tio.c_cc[VTIME] = 0;
tio.c_cc[VMIN] = 1;
tcflush(serialfd, TCIFLUSH);
tcsetattr(serialfd,TCSANOW,);
return 0;
}
Thank you for any help
--
Thomas
-
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problem with select() - 2.4.5
Hi !
I have a problem with reading from a serial port using select() under
2.4.5. What I am doing is basically the following:
fd_set readfds;
struct timeval timeout;
int s;
serialfd = open("/dev/ttyS0", O_RDWR );
init_serial(B9600);
timeout.tv_sec = 2; /* ! */
timeout.tv_usec = 0;
FD_ZERO();
FD_SET(serialfd,);
s=select(serialfd+1, , NULL, NULL, );
...
But s is always equal to 0 even when I am sure there are data to read.
If I use
s=select(serialfd+1, NULL, , NULL, );
(with the corresponding initialisation of writefds) it returns s=1 and I
can write to the serial port. I can see that since the lights of the modem
are flashing.
I noticed that behavior since I tried to send some "ATZ" with the
write-function but I never got the "OK" back.
However, the same programme works under 2.2.19.
Any help, please ?
--
Thomas
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
problem with select() - 2.4.5
Hi ! I have a problem with reading from a serial port using select() under 2.4.5. What I am doing is basically the following: fd_set readfds; struct timeval timeout; int s; serialfd = open(/dev/ttyS0, O_RDWR ); init_serial(B9600); timeout.tv_sec = 2; /* ! */ timeout.tv_usec = 0; FD_ZERO(readfds); FD_SET(serialfd,readfds); s=select(serialfd+1, readfds, NULL, NULL, timeout); ... But s is always equal to 0 even when I am sure there are data to read. If I use s=select(serialfd+1, NULL, writefds, NULL, timeout); (with the corresponding initialisation of writefds) it returns s=1 and I can write to the serial port. I can see that since the lights of the modem are flashing. I noticed that behavior since I tried to send some ATZ with the write-function but I never got the OK back. However, the same programme works under 2.2.19. Any help, please ? -- Thomas - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: problem with select() - 2.4.5
On Fri, 22 Jun 2001, Thomas Speck wrote:
Hi !
I have a problem with reading from a serial port using select() under
2.4.5. What I am doing is basically the following:
fd_set readfds;
struct timeval timeout;
int s;
serialfd = open(/dev/ttyS0, O_RDWR );
init_serial(B9600);
timeout.tv_sec = 2; /* ! */
timeout.tv_usec = 0;
FD_ZERO(readfds);
FD_SET(serialfd,readfds);
s=select(serialfd+1, readfds, NULL, NULL, timeout);
...
But s is always equal to 0 even when I am sure there are data to read.
If I use
s=select(serialfd+1, NULL, writefds, NULL, timeout);
(with the corresponding initialisation of writefds) it returns s=1 and I
can write to the serial port. I can see that since the lights of the modem
are flashing.
I noticed that behavior since I tried to send some ATZ with the
write-function but I never got the OK back.
However, the same programme works under 2.2.19.
Probably I should have given the init_serial() as well; So here it is:
(it is basically the one from the serial-programming-howto)
int init_serial(tcflag_t baud)
{
struct termios tio;
tcgetattr(serialfd,tio);
tio.c_cflag = baud | CLOCAL;
tio.c_iflag = IGNPAR;
tio.c_oflag = 0;
tio.c_lflag = 0;
tio.c_cc[VTIME] = 0;
tio.c_cc[VMIN] = 1;
tcflush(serialfd, TCIFLUSH);
tcsetattr(serialfd,TCSANOW,tio);
return 0;
}
Thank you for any help
--
Thomas
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: problem with select() - 2.4.5
Thomas Speck wrote: tio.c_cflag = baud | CLOCAL; How about adding CREAD? Ciao, ET. - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
