Revision e9840dc00468c4d2ca63b9f80038533d0f931d16 authored by Jarkko Nikula on 11 November 2009, 19:00:36 UTC, committed by Tony Lindgren on 11 November 2009, 19:04:09 UTC
The host port power is enabled by driving the nEN_USB_PWR low as stated in
the comment. This fix is originally from Steve Sakoman <steve@sakoman.com>.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Cc: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
1 parent 24de042
Raw File
dec_and_lock.c
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/atomic.h>

/*
 * This is an implementation of the notion of "decrement a
 * reference count, and return locked if it decremented to zero".
 *
 * NOTE NOTE NOTE! This is _not_ equivalent to
 *
 *	if (atomic_dec_and_test(&atomic)) {
 *		spin_lock(&lock);
 *		return 1;
 *	}
 *	return 0;
 *
 * because the spin-lock and the decrement must be
 * "atomic".
 */
int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
{
	/* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */
	if (atomic_add_unless(atomic, -1, 1))
		return 0;

	/* Otherwise do it the slow way */
	spin_lock(lock);
	if (atomic_dec_and_test(atomic))
		return 1;
	spin_unlock(lock);
	return 0;
}

EXPORT_SYMBOL(_atomic_dec_and_lock);
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