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authorThomas Gleixner <tglx@linutronix.de>2007-05-29 21:53:50 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2007-05-30 14:33:01 +0100
commit2389b272168ceec056ca1d8a870a97fa9c26e11a (patch)
treee3a8be37e9e97bb8e232fbe6bd7823799e6899c1 /drivers/serial
parent2ccdd1e77da52ad494e9af46bf272d816830cb28 (diff)
downloadlinux-2389b272168ceec056ca1d8a870a97fa9c26e11a.tar.gz
[ARM] 4417/1: Serial: Fix AMBA drivers locking
The -rt patch triggered a lockdep warning in the amba serial drivers, which never
shows up on UP kernels. On SMP systems this would trigger as well.

Release the port lock before calling tty_flip_buffer_push() and reacquire it after
the call. This matches the code in the 8250 serial driver.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'drivers/serial')
-rw-r--r--drivers/serial/amba-pl010.c3
-rw-r--r--drivers/serial/amba-pl011.c3
2 files changed, 4 insertions, 2 deletions
diff --git a/drivers/serial/amba-pl010.c b/drivers/serial/amba-pl010.c
index 1a9a24b82636..00d1255e4c12 100644
--- a/drivers/serial/amba-pl010.c
+++ b/drivers/serial/amba-pl010.c
@@ -167,8 +167,9 @@ static void pl010_rx_chars(struct uart_amba_port *uap)
 	ignore_char:
 		status = readb(uap->port.membase + UART01x_FR);
 	}
+	spin_unlock(&port->lock);
 	tty_flip_buffer_push(tty);
-	return;
+	spin_lock(&port->lock);
 }
 
 static void pl010_tx_chars(struct uart_amba_port *uap)
diff --git a/drivers/serial/amba-pl011.c b/drivers/serial/amba-pl011.c
index 44639e71372a..954073c6ce3a 100644
--- a/drivers/serial/amba-pl011.c
+++ b/drivers/serial/amba-pl011.c
@@ -153,8 +153,9 @@ static void pl011_rx_chars(struct uart_amba_port *uap)
 	ignore_char:
 		status = readw(uap->port.membase + UART01x_FR);
 	}
+	spin_unlock(&uap->port.lock);
 	tty_flip_buffer_push(tty);
-	return;
+	spin_lock(&uap->port.lock);
 }
 
 static void pl011_tx_chars(struct uart_amba_port *uap)