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[v4] serial: mctrl_gpio: add IRQ locking

Message ID 1461919507-17626-1-git-send-email-yegorslists@googlemail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Yegor Yefremov April 29, 2016, 8:45 a.m. UTC 
From: Yegor Yefremov <yegorslists@googlemail.com>

uart_handle_cts_change should be called with port->lock held. And for
this to be save you must also disable irqs.

Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
---
Changes:
	v4: move lock after mctrl_gpio_get (Uwe Kleine-König)
        v3: send this patch separately from the 8259 mctrl_gpio series
            and improve commit wording (Uwe Kleine-König)

 drivers/tty/serial/serial_mctrl_gpio.c | 5 +++++
 1 file changed, 5 insertions(+)
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Patch

diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c
index bb5e4f9..f18df52 100644
--- a/drivers/tty/serial/serial_mctrl_gpio.c
+++ b/drivers/tty/serial/serial_mctrl_gpio.c
@@ -143,9 +143,12 @@  static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context)
 	struct uart_port *port = gpios->port;
 	u32 mctrl = gpios->mctrl_prev;
 	u32 mctrl_diff;
+	unsigned long flags;
 
 	mctrl_gpio_get(gpios, &mctrl);
 
+	spin_lock_irqsave(&port->lock, flags);
+
 	mctrl_diff = mctrl ^ gpios->mctrl_prev;
 	gpios->mctrl_prev = mctrl;
 
@@ -165,6 +168,8 @@  static irqreturn_t mctrl_gpio_irq_handle(int irq, void *context)
 		wake_up_interruptible(&port->state->port.delta_msr_wait);
 	}
 
+	spin_unlock_irqrestore(&port->lock, flags);
+
 	return IRQ_HANDLED;
 }