Re: [PATCH] MPSC serial driver tx locking

From: Russell King
Date: Wed May 10 2006 - 12:26:44 EST


On Tue, May 09, 2006 at 05:35:52PM -0700, Dave Jiang wrote:
> @@ -1997,7 +2018,7 @@ mpsc_drv_probe(struct platform_device *d
> if (!(rc = mpsc_make_ready(pi)))
> if (!(rc = uart_add_one_port(&mpsc_reg,
> &pi->port)))
> - rc = 0;
> + spin_lock_init(&pi->tx_lock);

You publish the port to the uart layer and then do initialisation.
What if someone nips in and starts using the port between registering
it and initialising the spinlock? (that's a general principle - for
any device driver, never publish the device interfaces until you've
completed all initialisation.)

Why not do the spinlock initialisation first?

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core
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