Commit 0b91b533 authored by Zhenguo Zhao's avatar Zhenguo Zhao Committed by Greg Kroah-Hartman
Browse files

tty: n_gsm: Save dlci address open status when config requester 



When n_gsm config "initiator=0",as requester ,receive SABM frame,n_gsm
register gsmtty dev,and save dlci open address status,if receive DLC0
DISC or CLD frame,it can unregister the gsmtty dev by saving dlci address.

Signed-off-by: default avatarZhenguo Zhao <Zhenguo.Zhao1@unisoc.com>
Link: https://lore.kernel.org/r/1629461872-26965-8-git-send-email-zhenguo6858@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5b87686e

drivers/tty/n_gsm.c

+53 −4
Original line number Diff line number Diff line
@@ -271,6 +271,10 @@ static DEFINE_SPINLOCK(gsm_mux_lock); 


static struct tty_driver *gsm_tty_driver;



/* Save dlci open address */

static int addr_open[256] = { 0 };

/* Save dlci open count */

static int addr_cnt;

/*

 *	This section of the driver logic implements the GSM encodings

 *	both the basic and the 'advanced'. Reliable transport is not
@@ -1181,6 +1185,7 @@ static void gsm_control_rls(struct gsm_mux *gsm, const u8 *data, int clen) 
}



static void gsm_dlci_begin_close(struct gsm_dlci *dlci);

static void gsm_dlci_close(struct gsm_dlci *dlci);



/**

 *	gsm_control_message	-	DLCI 0 control processing
@@ -1199,15 +1204,28 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, 
{

	u8 buf[1];

	unsigned long flags;

	struct gsm_dlci *dlci;

	int i;

	int address;



	switch (command) {

	case CMD_CLD: {

		struct gsm_dlci *dlci = gsm->dlci[0];

		if (addr_cnt > 0) {

			for (i = 0; i < addr_cnt; i++) {

				address = addr_open[i];

				dlci = gsm->dlci[address];

				gsm_dlci_close(dlci);

				addr_open[i] = 0;

			}

		}

		/* Modem wishes to close down */

		dlci = gsm->dlci[0];

		if (dlci) {

			dlci->dead = true;

			gsm->dead = true;

			gsm_dlci_begin_close(dlci);

			gsm_dlci_close(dlci);

			addr_cnt = 0;

			gsm_response(gsm, 0, UA|PF);

		}

		}

		break;
@@ -1756,6 +1774,7 @@ static void gsm_queue(struct gsm_mux *gsm) 
	struct gsm_dlci *dlci;

	u8 cr;

	int address;

	int i, j, k, address_tmp;

	/* We have to sneak a look at the packet body to do the FCS.

	   A somewhat layering violation in the spec */
@@ -1798,6 +1817,11 @@ static void gsm_queue(struct gsm_mux *gsm) 
		else {

			gsm_response(gsm, address, UA|PF);

			gsm_dlci_open(dlci);

			/* Save dlci open address */

			if (address) {

				addr_open[addr_cnt] = address;

				addr_cnt++;

			}

		}

		break;

	case DISC|PF:
@@ -1808,8 +1832,33 @@ static void gsm_queue(struct gsm_mux *gsm) 
			return;

		}

		/* Real close complete */

		if (!address) {

			if (addr_cnt > 0) {

				for (i = 0; i < addr_cnt; i++) {

					address = addr_open[i];

					dlci = gsm->dlci[address];

					gsm_dlci_close(dlci);

					addr_open[i] = 0;

				}

			}

			dlci = gsm->dlci[0];

			gsm_dlci_close(dlci);

			addr_cnt = 0;

			gsm_response(gsm, 0, UA|PF);

		} else {

			gsm_response(gsm, address, UA|PF);

			gsm_dlci_close(dlci);

			/* clear dlci address */

			for (j = 0; j < addr_cnt; j++) {

				address_tmp = addr_open[j];

				if (address_tmp == address) {

					for (k = j; k < addr_cnt; k++)

						addr_open[k] = addr_open[k+1];

				addr_cnt--;

				break;

				}

			}

		}

		break;

	case UA:

	case UA|PF: