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SubjectRe: [PATCH v2] tty: n_gsm: CR bit value should be 0 when config "initiator=0"
Dear Jiri,Greg

1: our development board uses linux kernel , uart dev node is "/dev/ttyGS2"
2: config uart "/dev/ttyGS2" ,we use ngsm ldisc,and config
"c.initiator = 0;" code is as follows

#include <stdio.h>
#include <stdint.h>
#include <linux/gsmmux.h>
#include <linux/tty.h>
#define DEFAULT_SPEED B115200
#define SERIAL_PORT /dev/ttyGS2

int ldisc = N_GSM0710;
struct gsm_config c;
struct termios configuration;
uint32_t first;

/* open the serial port */
fd = open(SERIAL_PORT, O_RDWR | O_NOCTTY | O_NDELAY);

/* configure the serial port : speed, flow control ... */

/* use n_gsm line discipline */
ioctl(fd, TIOCSETD, &ldisc);

/* get n_gsm configuration */
ioctl(fd, GSMIOC_GETCONF, &c);
/* we are responter and need encoding 0 (basic) */
c.initiator = 0;
c.encapsulation = 0;
/* our modem defaults to a maximum size of 127 bytes */
c.mru = 127;
c.mtu = 127;
/* set the new configuration */
ioctl(fd, GSMIOC_SETCONF, &c);
/* get first gsmtty device node */
ioctl(fd, GSMIOC_GETFIRST, &first);
printf("first muxed line: /dev/gsmtty%i\n", first);

/* and wait for ever to keep the line discipline enabled */
daemon(0,0);
pause();

3: connect to ubuntu by uart serial port cable,ubuntu uart dev node
is /"dev/ttyUSB0"
send DLC0 SABM command by "/dev/ttyUSB0",but linux development board
can't response,code is as follows

int main(int argc, char **argv)
{
int fd;
fd = open("/dev/ttyUSB0,O_RDWR | O_NOCTTY | O_NDELAY);
char buf[256]={0xf9,0x03,0x3f,0x01,0x1c,0xf9};
write(fd,buf,6);
close(fd);
}

4: linux development board receive data,by uart,gsm_queue will check
CR,find CR=1.so go to invalid,pls check again.
static void gsm_queue(struct gsm_mux *gsm)
{
cr ^= 1 - gsm->initiator; /* Flip so 1 always means command */
dlci = gsm->dlci[address];

switch (gsm->control) {
case SABM|PF:
if (cr == 0)
goto invalid;
if (dlci == NULL)
dlci = gsm_dlci_alloc(gsm, address);
if (dlci == NULL)
return;
if (dlci->dead)
gsm_response(gsm, address, DM);
else {
gsm_response(gsm, address, UA);
gsm_dlci_open(dlci);
}
break;

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