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Commit f5fb743e authored by Karthikeyan Ramasubramanian's avatar Karthikeyan Ramasubramanian
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tty: serial: msm_geni_serial: Add get_mctrl console operation 



Add get_mctrl operation for console port so that reading the input control
signals does not cause any error.

When the system OOPS is in progress, try locking the console port
lock. If the locking fails, return immediately to avoid any recursive
locking.

Also when the UART port is shutdown stop the console followed by stopping
the TX/RX while holding the port lock. This will ensure that the port
shutdown operation does not prematurely stop the concerned serial engine
while another thread is waiting for the TX/RX lock.

CRs-Fixed: 2052028
Change-Id: Iaac8045dbad100e3754b88480869202ddce84b99
Signed-off-by: default avatarKarthikeyan Ramasubramanian <kramasub@codeaurora.org>
parent ea5149e3

drivers/tty/serial/msm_geni_serial.c

+25 −4
Original line number Diff line number Diff line
@@ -327,6 +327,11 @@ static void msm_geni_serial_break_ctl(struct uart_port *uport, int ctl) 
	mb();

}



static unsigned int msm_geni_cons_get_mctrl(struct uart_port *uport)

{

	return TIOCM_DSR | TIOCM_CAR | TIOCM_CTS;

}



static unsigned int msm_geni_serial_get_mctrl(struct uart_port *uport)

{

	u32 geni_ios = 0;
@@ -610,6 +615,8 @@ static void msm_geni_serial_console_write(struct console *co, const char *s, 
{

	struct uart_port *uport;

	struct msm_geni_serial_port *port;

	int locked = 1;

	unsigned long flags;



	WARN_ON(co->index < 0 || co->index >= GENI_UART_NR_PORTS);
@@ -618,9 +625,15 @@ static void msm_geni_serial_console_write(struct console *co, const char *s, 
		return;



	uport = &port->uport;

	spin_lock(&uport->lock);

	if (oops_in_progress)

		locked = spin_trylock_irqsave(&uport->lock, flags);

	else

		spin_lock_irqsave(&uport->lock, flags);



	if (locked) {

		__msm_geni_serial_console_write(uport, s, count);

	spin_unlock(&uport->lock);

		spin_unlock_irqrestore(&uport->lock, flags);

	}

}



static int handle_rx_console(struct uart_port *uport,
@@ -1014,13 +1027,20 @@ static void set_rfr_wm(struct msm_geni_serial_port *port) 
static void msm_geni_serial_shutdown(struct uart_port *uport)

{

	struct msm_geni_serial_port *msm_port = GET_DEV_PORT(uport);

	unsigned long flags;



	/* Stop the console before stopping the current tx */

	if (uart_console(uport))

		console_stop(uport->cons);



	spin_lock_irqsave(&uport->lock, flags);

	msm_geni_serial_stop_tx(uport);

	msm_geni_serial_stop_rx(uport);

	spin_unlock_irqrestore(&uport->lock, flags);



	disable_irq(uport->irq);

	free_irq(uport->irq, msm_port);

	if (uart_console(uport)) {

		console_stop(uport->cons);

		se_geni_resources_off(&msm_port->serial_rsc);

	} else {

		if (msm_port->wakeup_irq > 0) {
@@ -1572,6 +1592,7 @@ static const struct uart_ops msm_geni_console_pops = { 
	.shutdown = msm_geni_serial_shutdown,

	.type = msm_geni_serial_get_type,

	.set_mctrl = msm_geni_cons_set_mctrl,

	.get_mctrl = msm_geni_cons_get_mctrl,

#ifdef CONFIG_CONSOLE_POLL

	.poll_get_char	= msm_geni_serial_get_char,

	.poll_put_char	= msm_geni_serial_poll_put_char,