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Commit 978e595f authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
Browse files

tty/serial: lay the foundations for the next set of reworks 



- Stop drivers calling their own flush method indirectly, it obfuscates code
  and it will change soon anyway

- A few more lock_kernel paths temporarily needed in some driver internal
  waiting code

- Remove private put_char method that does a write call for one char - we
  have that anyway

- Most but not yet all of the termios copy under lock fixing (some has other
  dependencies to follow)

- Note a few locking bugs in drivers found in the process

- Kill remaining [ab]users of TIOCG/SSOFTCAR in the driver, these must go to
  fix the termios locking

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ac0e4b7d

drivers/char/amiserial.c

+4 −2
Original line number Diff line number Diff line
@@ -1505,8 +1505,7 @@ static void rs_close(struct tty_struct *tty, struct file * filp) 
		rs_wait_until_sent(tty, info->timeout);

	}

	shutdown(info);

	if (tty->driver->flush_buffer)

		tty->driver->flush_buffer(tty);

	rs_flush_buffer(tty);

		

	tty_ldisc_flush(tty);

	tty->closing = 0;
@@ -1539,6 +1538,8 @@ static void rs_wait_until_sent(struct tty_struct *tty, int timeout) 
		return; /* Just in case.... */



	orig_jiffies = jiffies;



	lock_kernel();

	/*

	 * Set the check interval to be 1/5 of the estimated time to

	 * send a single character, and make it at least 1.  The check
@@ -1579,6 +1580,7 @@ static void rs_wait_until_sent(struct tty_struct *tty, int timeout) 
			break;

	}

	__set_current_state(TASK_RUNNING);

	unlock_kernel();

#ifdef SERIAL_DEBUG_RS_WAIT_UNTIL_SENT

	printk("lsr = %d (jiff=%lu)...done\n", lsr, jiffies);

#endif

drivers/char/cyclades.c

+40 −36
Original line number Diff line number Diff line
@@ -2522,6 +2522,7 @@ static void cy_wait_until_sent(struct tty_struct *tty, int timeout) 
		return;		/* Just in case.... */



	orig_jiffies = jiffies;

	lock_kernel();

	/*

	 * Set the check interval to be 1/5 of the estimated time to

	 * send a single character, and make it at least 1.  The check
@@ -2573,11 +2574,47 @@ static void cy_wait_until_sent(struct tty_struct *tty, int timeout) 
	}

	/* Run one more char cycle */

	msleep_interruptible(jiffies_to_msecs(char_time * 5));

	unlock_kernel();

#ifdef CY_DEBUG_WAIT_UNTIL_SENT

	printk(KERN_DEBUG "Clean (jiff=%lu)...done\n", jiffies);

#endif

}



static void cy_flush_buffer(struct tty_struct *tty)

{

	struct cyclades_port *info = tty->driver_data;

	struct cyclades_card *card;

	int channel, retval;

	unsigned long flags;



#ifdef CY_DEBUG_IO

	printk(KERN_DEBUG "cyc:cy_flush_buffer ttyC%d\n", info->line);

#endif



	if (serial_paranoia_check(info, tty->name, "cy_flush_buffer"))

		return;



	card = info->card;

	channel = info->line - card->first_line;



	spin_lock_irqsave(&card->card_lock, flags);

	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;

	spin_unlock_irqrestore(&card->card_lock, flags);



	if (IS_CYC_Z(*card)) {	/* If it is a Z card, flush the on-board

					   buffers as well */

		spin_lock_irqsave(&card->card_lock, flags);

		retval = cyz_issue_cmd(card, channel, C_CM_FLUSH_TX, 0L);

		if (retval != 0) {

			printk(KERN_ERR "cyc: flush_buffer retval on ttyC%d "

				"was %x\n", info->line, retval);

		}

		spin_unlock_irqrestore(&card->card_lock, flags);

	}

	tty_wakeup(tty);

}				/* cy_flush_buffer */





/*

 * This routine is called when a particular tty device is closed.

 */
@@ -2689,8 +2726,7 @@ static void cy_close(struct tty_struct *tty, struct file *filp) 


	spin_unlock_irqrestore(&card->card_lock, flags);

	shutdown(info);

	if (tty->driver->flush_buffer)

		tty->driver->flush_buffer(tty);

	cy_flush_buffer(tty);

	tty_ldisc_flush(tty);

	spin_lock_irqsave(&card->card_lock, flags);
@@ -2881,6 +2917,7 @@ static int cy_chars_in_buffer(struct tty_struct *tty) 
		int char_count;

		__u32 tx_put, tx_get, tx_bufsize;



		lock_kernel();

		firm_id = card->base_addr + ID_ADDRESS;

		zfw_ctrl = card->base_addr +

			(readl(&firm_id->zfwctrl_addr) & 0xfffff);
@@ -2898,6 +2935,7 @@ static int cy_chars_in_buffer(struct tty_struct *tty) 
		printk(KERN_DEBUG "cyc:cy_chars_in_buffer ttyC%d %d\n",

			info->line, info->xmit_cnt + char_count);

#endif

		unlock_kernel();

		return info->xmit_cnt + char_count;

	}

#endif				/* Z_EXT_CHARS_IN_BUFFER */
@@ -4271,40 +4309,6 @@ static void cy_start(struct tty_struct *tty) 
	}

}				/* cy_start */



static void cy_flush_buffer(struct tty_struct *tty)

{

	struct cyclades_port *info = tty->driver_data;

	struct cyclades_card *card;

	int channel, retval;

	unsigned long flags;



#ifdef CY_DEBUG_IO

	printk(KERN_DEBUG "cyc:cy_flush_buffer ttyC%d\n", info->line);

#endif



	if (serial_paranoia_check(info, tty->name, "cy_flush_buffer"))

		return;



	card = info->card;

	channel = info->line - card->first_line;



	spin_lock_irqsave(&card->card_lock, flags);

	info->xmit_cnt = info->xmit_head = info->xmit_tail = 0;

	spin_unlock_irqrestore(&card->card_lock, flags);



	if (IS_CYC_Z(*card)) {	/* If it is a Z card, flush the on-board

					   buffers as well */

		spin_lock_irqsave(&card->card_lock, flags);

		retval = cyz_issue_cmd(card, channel, C_CM_FLUSH_TX, 0L);

		if (retval != 0) {

			printk(KERN_ERR "cyc: flush_buffer retval on ttyC%d "

				"was %x\n", info->line, retval);

		}

		spin_unlock_irqrestore(&card->card_lock, flags);

	}

	tty_wakeup(tty);

}				/* cy_flush_buffer */



/*

 * cy_hangup() --- called by tty_hangup() when a hangup is signaled.

 */

drivers/char/epca.c

+2 −11
Original line number Diff line number Diff line
@@ -157,7 +157,6 @@ static void epca_error(int, char *); 
static void pc_close(struct tty_struct *, struct file *);

static void shutdown(struct channel *);

static void pc_hangup(struct tty_struct *);

static void pc_put_char(struct tty_struct *, unsigned char);

static int pc_write_room(struct tty_struct *);

static int pc_chars_in_buffer(struct tty_struct *);

static void pc_flush_buffer(struct tty_struct *);
@@ -459,8 +458,7 @@ static void pc_close(struct tty_struct *tty, struct file *filp) 
			setup_empty_event(tty, ch);

			tty_wait_until_sent(tty, 3000); /* 30 seconds timeout */

		}

		if (tty->driver->flush_buffer)

			tty->driver->flush_buffer(tty);

		pc_flush_buffer(tty);



		tty_ldisc_flush(tty);

		shutdown(ch);
@@ -532,8 +530,7 @@ static void pc_hangup(struct tty_struct *tty) 
	if ((ch = verifyChannel(tty)) != NULL) {

		unsigned long flags;



		if (tty->driver->flush_buffer)

			tty->driver->flush_buffer(tty);

		pc_flush_buffer(tty);

		tty_ldisc_flush(tty);

		shutdown(ch);
@@ -645,11 +642,6 @@ static int pc_write(struct tty_struct *tty, 
	return amountCopied;

}



static void pc_put_char(struct tty_struct *tty, unsigned char c)

{

	pc_write(tty, &c, 1);

}



static int pc_write_room(struct tty_struct *tty)

{

	int remain;
@@ -1035,7 +1027,6 @@ static const struct tty_operations pc_ops = { 
	.flush_buffer = pc_flush_buffer,

	.chars_in_buffer = pc_chars_in_buffer,

	.flush_chars = pc_flush_chars,

	.put_char = pc_put_char,

	.ioctl = pc_ioctl,

	.set_termios = pc_set_termios,

	.stop = pc_stop,

drivers/char/esp.c

+1 −2
Original line number Diff line number Diff line
@@ -1994,8 +1994,7 @@ static void rs_close(struct tty_struct *tty, struct file * filp) 
		rs_wait_until_sent(tty, info->timeout);

	}

	shutdown(info);

	if (tty->driver->flush_buffer)

		tty->driver->flush_buffer(tty);

	rs_flush_buffer(tty);

	tty_ldisc_flush(tty);

	tty->closing = 0;

	info->tty = NULL;

drivers/char/generic_serial.c

+1 −2
Original line number Diff line number Diff line
@@ -586,8 +586,7 @@ void gs_close(struct tty_struct * tty, struct file * filp) 


	port->flags &= ~GS_ACTIVE;



	if (tty->driver->flush_buffer)

		tty->driver->flush_buffer(tty);

	gs_flush_buffer(tty);



	tty_ldisc_flush(tty);

	tty->closing = 0;