[PATCH] BUG: atmel_serial: Interrupts not disabled on close
Richard Genoud
richard.genoud at gmail.com
Mon Sep 12 06:34:41 PDT 2016
Since commit 18dfef9c7f87 ("serial: atmel: convert to irq handling
provided mctrl-gpio"), interrupts from GPIOs are not disabled any more
when the serial port is closed, leading to an oops when the one of the
input pin is toggled (CTS/DSR/DCD/RNG).
This is only the case if those pins are used as GPIOs, i.e. declared
like that:
usart1: serial at f8020000 {
/* CTS and DTS will be handled by GPIO */
status = "okay";
rts-gpios = <&pioB 17 GPIO_ACTIVE_LOW>;
cts-gpios = <&pioB 16 GPIO_ACTIVE_LOW>;
dtr-gpios = <&pioB 14 GPIO_ACTIVE_LOW>;
dsr-gpios = <&pioC 31 GPIO_ACTIVE_LOW>;
rng-gpios = <&pioB 12 GPIO_ACTIVE_LOW>;
dcd-gpios = <&pioB 15 GPIO_ACTIVE_LOW>;
};
That's because modem interrupts used to be freed in atmel_shutdown().
After commit 18dfef9c7f87 ("serial: atmel: convert to irq handling
provided mctrl-gpio"), this code was just removed.
Calling atmel_disable_ms() disables the interrupts and everything works
fine again.
Tested on at91sam9g35-cm
(This patch doesn't apply on -stable kernels, fixes for 4.4 and 4.7 will
be sent after this one is applied.)
Signed-off-by: Richard Genoud <richard.genoud at gmail.com>
Fixes: 18dfef9c7f87 ("serial: atmel: convert to irq handling provided mctrl-gpio")
---
drivers/tty/serial/atmel_serial.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index 2eaa18ddef61..8bbde52db376 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1929,6 +1929,9 @@ static void atmel_shutdown(struct uart_port *port)
{
struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
+ /* Disable modem control lines interrupts */
+ atmel_disable_ms(port);
+
/* Disable interrupts at device level */
atmel_uart_writel(port, ATMEL_US_IDR, -1);
@@ -1979,8 +1982,6 @@ static void atmel_shutdown(struct uart_port *port)
*/
free_irq(port->irq, port);
- atmel_port->ms_irq_enabled = false;
-
atmel_flush_buffer(port);
}
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