[PATCH v2 4/9] serial: fsl_lpuart: split sysrq handling

From: Michael Walle
Date: Wed May 12 2021 - 10:14:07 EST


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: Johan Hovold <johan@xxxxxxxxxx>
Signed-off-by: Michael Walle <michael@xxxxxxxx>
---
drivers/tty/serial/fsl_lpuart.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 37e02d992c0b..63a1dac7c3aa 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -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);
--
2.20.1