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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: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
hifive-unleashed-5.1
Thomas Gleixner 2007-05-29 21:53:50 +01:00 committed by Russell King
parent 2ccdd1e77d
commit 2389b27216
2 changed files with 4 additions and 2 deletions
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3
drivers/serial/amba-pl010.c
View File

@ -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)

3
drivers/serial/amba-pl011.c
View File

@ -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)