Re: [PATCH] parport: make lockdep happy with waitlist_lock

From: Ingo Molnar
Date: Mon Jan 24 2011 - 10:28:43 EST



* Alexander Gordeev <lasaine@xxxxxxxxxxxxx> wrote:

> parport_unregister_device should never be used when interrupts are
> enabled in hardware and irq handler is registered so there is no need
> to disable interrupts when using waitlist_lock. But there is no way to
> explain this subtle semantics to lockdep analyzer. So disable interrupts
> here too to simplify things. The price is negligible.
>
> Signed-off-by: Alexander Gordeev <lasaine@xxxxxxxxxxxxx>
> ---
> drivers/parport/share.c | 4 ++--
> 1 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/parport/share.c b/drivers/parport/share.c
> index a2d9d1e..c3dd1a3 100644
> --- a/drivers/parport/share.c
> +++ b/drivers/parport/share.c
> @@ -678,7 +678,7 @@ void parport_unregister_device(struct pardevice *dev)
>
> /* Make sure we haven't left any pointers around in the wait
> * list. */
> - spin_lock (&port->waitlist_lock);
> + spin_lock_irq (&port->waitlist_lock);

Small detail: please use a consistent coding style, i.e. 'spin_lock_irq(', not
'spin_lock_irq ('.

Thanks,

Ingo
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