Re: [PATCH 2.6.17-rc1] [SERIAL] DCC(JTAG) serial and the console emulation support(revised#2)

[Russell King <rmk+lkml@arm.linux.org.uk>]

On Tue, Apr 04, 2006 at 11:27:06AM +0900, Hyok S. Choi wrote:
> On Tuesday 04 April 2006 04:44 am, Russell King wrote:
> > On Mon, Apr 03, 2006 at 08:24:10PM +0900, Hyok S. Choi wrote:
> > 
> > > +static void dcc_shutdown(struct uart_port *port)
> > > +{
> > > +#ifdef DCC_IRQ_USED /* real IRQ used */
> > > +	free_irq(port->irq, port);
> > > +#else
> > > +	spin_lock(&port->lock);
> > > +	cancel_rearming_delayed_work(&dcc_poll_task);
> > 
> > cancel_rearming_delayed_work() might sleep due to it calling
> > flush_workqueue.  Therefore, you must not be holding a spinlock.
> 
> Thus, I've just revised the code to lock around a counter variable
> operation, which is used for life control of the polling task.
> I've just posted the revised #3. :-)

Why do you think you need such complexity?

cancel_rearming_delayed_work() will wait until the poll task has
completed and has been removed from the system.  It's explicitly
designed for work handlers which self-rearm.

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