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Commit 2389b272 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Russell King
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[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: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 2ccdd1e7

drivers/serial/amba-pl010.c

+2 −1
Original line number Original line Diff line number Diff line
@@ -167,8 +167,9 @@ static void pl010_rx_chars(struct uart_amba_port *uap) 
	ignore_char:

	ignore_char:

		status = readb(uap->port.membase + UART01x_FR);

		status = readb(uap->port.membase + UART01x_FR);

	}

	}

	spin_unlock(&port->lock);

	tty_flip_buffer_push(tty);

	tty_flip_buffer_push(tty);

	return;

	spin_lock(&port->lock);

}

}





static void pl010_tx_chars(struct uart_amba_port *uap)

static void pl010_tx_chars(struct uart_amba_port *uap)

drivers/serial/amba-pl011.c

+2 −1
Original line number Original line Diff line number Diff line
@@ -153,8 +153,9 @@ static void pl011_rx_chars(struct uart_amba_port *uap) 
	ignore_char:

	ignore_char:

		status = readw(uap->port.membase + UART01x_FR);

		status = readw(uap->port.membase + UART01x_FR);

	}

	}

	spin_unlock(&uap->port.lock);

	tty_flip_buffer_push(tty);

	tty_flip_buffer_push(tty);

	return;

	spin_lock(&uap->port.lock);

}

}





static void pl011_tx_chars(struct uart_amba_port *uap)

static void pl011_tx_chars(struct uart_amba_port *uap)