Commit 5697df73 authored by Michael Walle's avatar Michael Walle Committed by Greg Kroah-Hartman
Browse files

serial: fsl_lpuart: split sysrq handling 



Instead of uart_handle_sysrq_char() use uart_prepare_sysrq_char() and
uart_unlock_and_check_sysrq(). This will call handle_sysrq() without
holding the port lock, which in turn let us drop the spin_trylock hack.

Suggested-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarMichael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20210512141255.18277-5-michael@walle.cc


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0d84f622

drivers/tty/serial/fsl_lpuart.c

+6 −6
Original line number Diff line number Diff line
@@ -847,7 +847,7 @@ static void lpuart_rxint(struct lpuart_port *sport) 
		sr = readb(sport->port.membase + UARTSR1);

		rx = readb(sport->port.membase + UARTDR);



		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))

		if (uart_prepare_sysrq_char(&sport->port, rx))

			continue;



		if (sr & (UARTSR1_PE | UARTSR1_OR | UARTSR1_FE)) {
@@ -893,7 +893,7 @@ static void lpuart_rxint(struct lpuart_port *sport) 
		writeb(UARTSFIFO_RXOF, sport->port.membase + UARTSFIFO);

	}



	spin_unlock(&sport->port.lock);

	uart_unlock_and_check_sysrq(&sport->port);



	tty_flip_buffer_push(port);

}
@@ -924,7 +924,7 @@ static void lpuart32_rxint(struct lpuart_port *sport) 
		rx = lpuart32_read(&sport->port, UARTDATA);

		rx &= UARTDATA_MASK;



		if (uart_handle_sysrq_char(&sport->port, rx))

		if (uart_prepare_sysrq_char(&sport->port, rx))

			continue;



		if (sr & (UARTSTAT_PE | UARTSTAT_OR | UARTSTAT_FE)) {
@@ -959,7 +959,7 @@ static void lpuart32_rxint(struct lpuart_port *sport) 
	}



out:

	spin_unlock(&sport->port.lock);

	uart_unlock_and_check_sysrq(&sport->port);



	tty_flip_buffer_push(port);

}
@@ -2272,7 +2272,7 @@ lpuart_console_write(struct console *co, const char *s, unsigned int count) 
	unsigned long flags;

	int locked = 1;



	if (sport->port.sysrq || oops_in_progress)

	if (oops_in_progress)

		locked = spin_trylock_irqsave(&sport->port.lock, flags);

	else

		spin_lock_irqsave(&sport->port.lock, flags);
@@ -2302,7 +2302,7 @@ lpuart32_console_write(struct console *co, const char *s, unsigned int count) 
	unsigned long flags;

	int locked = 1;



	if (sport->port.sysrq || oops_in_progress)

	if (oops_in_progress)

		locked = spin_trylock_irqsave(&sport->port.lock, flags);

	else

		spin_lock_irqsave(&sport->port.lock, flags);