Commit 239ef19e authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

mxser: extract TX empty check from mxser_wait_until_sent() 



And move it to new mxser_tx_empty(), because:
1) it simplifies the code (esp. the locking), and
2) serial_core needs such a hook anyway, so have it ready.

Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20211118073125.12283-12-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent c7ec012f

drivers/tty/mxser.c

+13 −7
Original line number Diff line number Diff line
@@ -1402,6 +1402,18 @@ static void mxser_set_termios(struct tty_struct *tty, struct ktermios *old_termi 
	}

}



static bool mxser_tx_empty(struct mxser_port *info)

{

	unsigned long flags;

	u8 lsr;



	spin_lock_irqsave(&info->slock, flags);

	lsr = inb(info->ioaddr + UART_LSR);

	spin_unlock_irqrestore(&info->slock, flags);



	return !(lsr & UART_LSR_TEMT);

}



/*

 * mxser_wait_until_sent() --- wait until the transmitter is empty

 */
@@ -1409,8 +1421,6 @@ static void mxser_wait_until_sent(struct tty_struct *tty, int timeout) 
{

	struct mxser_port *info = tty->driver_data;

	unsigned long orig_jiffies, char_time;

	unsigned long flags;

	int lsr;



	if (info->type == PORT_UNKNOWN)

		return;
@@ -1445,17 +1455,13 @@ static void mxser_wait_until_sent(struct tty_struct *tty, int timeout) 
	if (!timeout || timeout > 2 * info->timeout)

		timeout = 2 * info->timeout;



	spin_lock_irqsave(&info->slock, flags);

	while (!((lsr = inb(info->ioaddr + UART_LSR)) & UART_LSR_TEMT)) {

		spin_unlock_irqrestore(&info->slock, flags);

	while (mxser_tx_empty(info)) {

		schedule_timeout_interruptible(char_time);

		spin_lock_irqsave(&info->slock, flags);

		if (signal_pending(current))

			break;

		if (timeout && time_after(jiffies, orig_jiffies + timeout))

			break;

	}

	spin_unlock_irqrestore(&info->slock, flags);

	set_current_state(TASK_RUNNING);

}