8390.c knows that ei_local->page_lock can only be used by an irq context that
it disabled - and can hence take the ->page_lock without disabling hardirqs.
Teach lockdep about this.
Has no effect on non-lockdep kernels.
Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>