Unverified Commit ce9f1089 authored by openeuler-ci-bot's avatar openeuler-ci-bot Committed by Gitee
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!13232 Revert "tty: n_gsm: avoid call of sleeping functions from atomic context" 

Merge Pull Request from: @ci-robot 
 
PR sync from: Yi Yang <yiyang13@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/ZQNW5UUBCDTIU4AD4S5AKMTIGDJWV5LB/ 
 
https://gitee.com/openeuler/kernel/issues/I7NTXH 
 
Link:https://gitee.com/openeuler/kernel/pulls/13232

 

Reviewed-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
parents ea638435 dd8f0f73

drivers/tty/n_gsm.c

+21 −18
Original line number Diff line number Diff line
@@ -235,7 +235,7 @@ struct gsm_mux { 
	int old_c_iflag;		/* termios c_iflag value before attach */

	bool constipated;		/* Asked by remote to shut up */



	struct mutex tx_mutex;

	spinlock_t tx_lock;

	unsigned int tx_bytes;		/* TX data outstanding */

#define TX_THRESH_HI		8192

#define TX_THRESH_LO		2048
@@ -820,14 +820,15 @@ static void __gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) 
 *

 *	Add data to the transmit queue and try and get stuff moving

 *	out of the mux tty if not already doing so. Take the

 *	the gsm tx mutex and dlci lock.

 *	the gsm tx lock and dlci lock.

 */



static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg)

{

	mutex_lock(&dlci->gsm->tx_mutex);

	unsigned long flags;

	spin_lock_irqsave(&dlci->gsm->tx_lock, flags);

	__gsm_data_queue(dlci, msg);

	mutex_unlock(&dlci->gsm->tx_mutex);

	spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);

}



/**
@@ -839,7 +840,7 @@ static void gsm_data_queue(struct gsm_dlci *dlci, struct gsm_msg *msg) 
 *	is data. Keep to the MRU of the mux. This path handles the usual tty

 *	interface which is a byte stream with optional modem data.

 *

 *	Caller must hold the tx_mutex of the mux.

 *	Caller must hold the tx_lock of the mux.

 */



static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci)
@@ -902,7 +903,7 @@ static int gsm_dlci_data_output(struct gsm_mux *gsm, struct gsm_dlci *dlci) 
 *	is data. Keep to the MRU of the mux. This path handles framed data

 *	queued as skbuffs to the DLCI.

 *

 *	Caller must hold the tx_mutex of the mux.

 *	Caller must hold the tx_lock of the mux.

 */



static int gsm_dlci_data_output_framed(struct gsm_mux *gsm,
@@ -918,7 +919,7 @@ static int gsm_dlci_data_output_framed(struct gsm_mux *gsm, 
	if (dlci->adaption == 4)

		overhead = 1;



	/* dlci->skb is locked by tx_mutex */

	/* dlci->skb is locked by tx_lock */

	if (dlci->skb == NULL) {

		dlci->skb = skb_dequeue_tail(&dlci->skb_list);

		if (dlci->skb == NULL)
@@ -1018,12 +1019,13 @@ static void gsm_dlci_data_sweep(struct gsm_mux *gsm) 


static void gsm_dlci_data_kick(struct gsm_dlci *dlci)

{

	unsigned long flags;

	int sweep;



	if (dlci->constipated)

		return;



	mutex_lock(&dlci->gsm->tx_mutex);

	spin_lock_irqsave(&dlci->gsm->tx_lock, flags);

	/* If we have nothing running then we need to fire up */

	sweep = (dlci->gsm->tx_bytes < TX_THRESH_LO);

	if (dlci->gsm->tx_bytes == 0) {
@@ -1034,7 +1036,7 @@ static void gsm_dlci_data_kick(struct gsm_dlci *dlci) 
	}

	if (sweep)

		gsm_dlci_data_sweep(dlci->gsm);

	mutex_unlock(&dlci->gsm->tx_mutex);

	spin_unlock_irqrestore(&dlci->gsm->tx_lock, flags);

}



/*
@@ -1256,6 +1258,7 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, 
						const u8 *data, int clen)

{

	u8 buf[1];

	unsigned long flags;



	switch (command) {

	case CMD_CLD: {
@@ -1277,9 +1280,9 @@ static void gsm_control_message(struct gsm_mux *gsm, unsigned int command, 
		gsm->constipated = false;

		gsm_control_reply(gsm, CMD_FCON, NULL, 0);

		/* Kick the link in case it is idling */

		mutex_lock(&gsm->tx_mutex);

		spin_lock_irqsave(&gsm->tx_lock, flags);

		gsm_data_kick(gsm, NULL);

		mutex_unlock(&gsm->tx_mutex);

		spin_unlock_irqrestore(&gsm->tx_lock, flags);

		break;

	case CMD_FCOFF:

		/* Modem wants us to STFU */
@@ -2230,7 +2233,6 @@ static void gsm_free_mux(struct gsm_mux *gsm) 
			break;

		}

	}

	mutex_destroy(&gsm->tx_mutex);

	mutex_destroy(&gsm->mutex);

	kfree(gsm->txframe);

	kfree(gsm->buf);
@@ -2302,12 +2304,12 @@ static struct gsm_mux *gsm_alloc_mux(void) 
	}

	spin_lock_init(&gsm->lock);

	mutex_init(&gsm->mutex);

	mutex_init(&gsm->tx_mutex);

	kref_init(&gsm->ref);

	INIT_LIST_HEAD(&gsm->tx_list);

	timer_setup(&gsm->t2_timer, gsm_control_retransmit, 0);

	init_waitqueue_head(&gsm->event);

	spin_lock_init(&gsm->control_lock);

	spin_lock_init(&gsm->tx_lock);



	gsm->t1 = T1;

	gsm->t2 = T2;
@@ -2332,7 +2334,6 @@ static struct gsm_mux *gsm_alloc_mux(void) 
	}

	spin_unlock(&gsm_mux_lock);

	if (i == MAX_MUX) {

		mutex_destroy(&gsm->tx_mutex);

		mutex_destroy(&gsm->mutex);

		kfree(gsm->txframe);

		kfree(gsm->buf);
@@ -2660,15 +2661,16 @@ static int gsmld_open(struct tty_struct *tty) 
static void gsmld_write_wakeup(struct tty_struct *tty)

{

	struct gsm_mux *gsm = tty->disc_data;

	unsigned long flags;



	/* Queue poll */

	clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);

	mutex_lock(&gsm->tx_mutex);

	spin_lock_irqsave(&gsm->tx_lock, flags);

	gsm_data_kick(gsm, NULL);

	if (gsm->tx_bytes < TX_THRESH_LO) {

		gsm_dlci_data_sweep(gsm);

	}

	mutex_unlock(&gsm->tx_mutex);

	spin_unlock_irqrestore(&gsm->tx_lock, flags);

}



/**
@@ -2711,6 +2713,7 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file, 
			   const unsigned char *buf, size_t nr)

{

	struct gsm_mux *gsm = tty->disc_data;

	unsigned long flags;

	int space;

	int ret;
@@ -2718,13 +2721,13 @@ static ssize_t gsmld_write(struct tty_struct *tty, struct file *file, 
		return -ENODEV;



	ret = -ENOBUFS;

	mutex_lock(&gsm->tx_mutex);

	spin_lock_irqsave(&gsm->tx_lock, flags);

	space = tty_write_room(tty);

	if (space >= nr)

		ret = tty->ops->write(tty, buf, nr);

	else

		set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);

	mutex_unlock(&gsm->tx_mutex);

	spin_unlock_irqrestore(&gsm->tx_lock, flags);



	return ret;

}