diff mbox

[08/25] tty: serial: efm32: drop uart_port->lock before calling tty_flip_buffer_push()

Message ID 41721e2fcd0a0eff70f990afa37163e55c6f7480.1376651114.git.viresh.kumar@linaro.org
State New
Headers show

Commit Message

Viresh Kumar Aug. 16, 2013, 11:43 a.m. UTC 
The -rt patch triggers a lockdep warning for serial drivers if
tty_flip_buffer_push() is called with uart_port->lock locked. This never shows
up on UP kernels.

Release the port lock before calling tty_flip_buffer_push() and reacquire it
after the call.

Similar stuff was already done for few other drivers in the past, like:

commit 2389b272168ceec056ca1d8a870a97fa9c26e11a
Author: Thomas Gleixner <tglx@linutronix.de>
Date:   Tue May 29 21:53:50 2007 +0100

    [ARM] 4417/1: Serial: Fix AMBA drivers locking

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
 drivers/tty/serial/efm32-uart.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/drivers/tty/serial/efm32-uart.c b/drivers/tty/serial/efm32-uart.c
index 7d199c8..b4cef79 100644
--- a/drivers/tty/serial/efm32-uart.c
+++ b/drivers/tty/serial/efm32-uart.c
@@ -268,10 +268,10 @@  static irqreturn_t efm32_uart_rxirq(int irq, void *data)
 		handled = IRQ_HANDLED;
 	}
 
-	tty_flip_buffer_push(tport);
-
 	spin_unlock(&port->lock);
 
+	tty_flip_buffer_push(tport);
+
 	return handled;
 }