From aa05931abcfbce651eac6fe68d39c3c60a4da3a4 Mon Sep 17 00:00:00 2001 From: "Jiri Slaby (SUSE)" Date: Wed, 11 Jun 2025 12:03:03 +0200 Subject: [PATCH] serial: 8250: extract serial8250_clear_interrupts() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit On three places in 8250_port.c, the interrupts are cleared by reading 4 registers. Extract this to a separate function: serial8250_clear_interrupts(). And call it from all the places. Note autoconfig_irq() now uses serial_port_in() instead of serial_in(). But they are the same, in fact (modulo parameter). Signed-off-by: "Jiri Slaby (SUSE)" Reviewed-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20250611100319.186924-18-jirislaby@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_port.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 6851c197b31de..a73f4db22feb2 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -705,6 +705,15 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) serial8250_rpm_put(p); } +/* Clear the interrupt registers. */ +static void serial8250_clear_interrupts(struct uart_port *port) +{ + serial_port_in(port, UART_LSR); + serial_port_in(port, UART_RX); + serial_port_in(port, UART_IIR); + serial_port_in(port, UART_MSR); +} + static void serial8250_clear_IER(struct uart_8250_port *up) { if (up->capabilities & UART_CAP_UUE) @@ -1275,10 +1284,7 @@ static void autoconfig_irq(struct uart_8250_port *up) uart_port_lock_irq(port); serial_out(up, UART_IER, UART_IER_ALL_INTR); uart_port_unlock_irq(port); - serial_in(up, UART_LSR); - serial_in(up, UART_RX); - serial_in(up, UART_IIR); - serial_in(up, UART_MSR); + serial8250_clear_interrupts(port); serial_out(up, UART_TX, 0xFF); udelay(20); irq = probe_irq_off(irqs); @@ -2322,13 +2328,7 @@ int serial8250_do_startup(struct uart_port *port) */ serial8250_clear_fifos(up); - /* - * Clear the interrupt registers. - */ - serial_port_in(port, UART_LSR); - serial_port_in(port, UART_RX); - serial_port_in(port, UART_IIR); - serial_port_in(port, UART_MSR); + serial8250_clear_interrupts(port); /* * At this point, there's no way the LSR could still be 0xff; @@ -2363,10 +2363,7 @@ int serial8250_do_startup(struct uart_port *port) * saved flags to avoid getting false values from polling * routines or the previous session. */ - serial_port_in(port, UART_LSR); - serial_port_in(port, UART_RX); - serial_port_in(port, UART_IIR); - serial_port_in(port, UART_MSR); + serial8250_clear_interrupts(port); up->lsr_saved_flags = 0; up->msr_saved_flags = 0; -- 2.51.0