From c389d27b5e643d745f55ffb939b1426060ba63d4 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Tue, 29 Jul 2008 22:33:32 -0700 Subject: [PATCH] 8250.c: port.lock is irq-safe serial8250_startup() doesn't disable interrupts while taking the &up->port.lock which might race against the interrupt handler serial8250_interrupt(), which when entered, will deadlock waiting for the lock to be released. Signed-off-by: Borislav Petkov Tested-by: Ingo Molnar Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/serial/8250.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index a97f1ae11f..342e12fb1c 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1885,7 +1885,7 @@ static int serial8250_startup(struct uart_port *port) * the interrupt is enabled. Delays are necessary to * allow register changes to become visible. */ - spin_lock(&up->port.lock); + spin_lock_irqsave(&up->port.lock, flags); if (up->port.flags & UPF_SHARE_IRQ) disable_irq_nosync(up->port.irq); @@ -1901,7 +1901,7 @@ static int serial8250_startup(struct uart_port *port) if (up->port.flags & UPF_SHARE_IRQ) enable_irq(up->port.irq); - spin_unlock(&up->port.lock); + spin_unlock_irqrestore(&up->port.lock, flags); /* * If the interrupt is not reasserted, setup a timer to -- 2.39.5