irqdomain: Avoid activating interrupts more than once

Since commit f3b0946d629c ("genirq/msi: Make sure PCI MSIs are
activated early"), we can end-up activating a PCI/MSI twice (once
at allocation time, and once at startup time).

This is normally of no consequences, except that there is some
HW out there that may misbehave if activate is used more than once
(the GICv3 ITS, for example, uses the activate callback
to issue the MAPVI command, and the architecture spec says that
"If there is an existing mapping for the EventID-DeviceID
combination, behavior is UNPREDICTABLE").

While this could be worked around in each individual driver, it may
make more sense to tackle the issue at the core level. In order to
avoid getting in that situation, let's have a per-interrupt flag
to remember if we have already activated that interrupt or not.

Fixes: f3b0946d629c ("genirq/msi: Make sure PCI MSIs are activated early")
Reported-and-tested-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1484668848-24361-1-git-send-email-marc.zyngier@arm.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

path: root/drivers/usb/chipidea/otg.h

/*
 * Copyright (C) 2013-2014 Freescale Semiconductor, Inc.
 *
 * Author: Peter Chen
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#ifndef __DRIVERS_USB_CHIPIDEA_OTG_H
#define __DRIVERS_USB_CHIPIDEA_OTG_H

u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask);
void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data);
int ci_hdrc_otg_init(struct ci_hdrc *ci);
void ci_hdrc_otg_destroy(struct ci_hdrc *ci);
enum ci_role ci_otg_role(struct ci_hdrc *ci);
void ci_handle_vbus_change(struct ci_hdrc *ci);
static inline void ci_otg_queue_work(struct ci_hdrc *ci)
{
	disable_irq_nosync(ci->irq);
	queue_work(ci->wq, &ci->work);
}

#endif /* __DRIVERS_USB_CHIPIDEA_OTG_H */