From 0ae9fdefb6c37237d826d6195e27810ffcc0b6e0 Mon Sep 17 00:00:00 2001 From: Richard Genoud Date: Mon, 12 Sep 2016 15:34:41 +0200 Subject: [PATCH] BUG: atmel_serial: Interrupts not disabled on close MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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@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 Fixes: 18dfef9c7f87 ("serial: atmel: convert to irq handling provided mctrl-gpio") Acked-by: Nicolas Ferre Acked-by: Uwe Kleine-König Signed-off-by: Greg Kroah-Hartman --- 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 72064b5e4f36..5f550d9feed9 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -1937,6 +1937,9 @@ 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); @@ -1987,8 +1990,6 @@ static void atmel_shutdown(struct uart_port *port) */ free_irq(port->irq, port); - atmel_port->ms_irq_enabled = false; - atmel_flush_buffer(port); } -- 2.20.1