From c942cee46bba761ce97ee6d4fc71892e064e8628 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Wed, 13 Sep 2017 23:29:09 +0200
Subject: genirq: Separate activation and startup

Activation of an interrupt and startup are currently a combo
functionlity. That works so far, but upcoming changes require a strict
separation because the activation can fail in future.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Juergen Gross <jgross@suse.com>
Tested-by: Yu Chen <yu.c.chen@intel.com>
Acked-by: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Alok Kataria <akataria@vmware.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rui Zhang <rui.zhang@intel.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Len Brown <lenb@kernel.org>
Link: https://lkml.kernel.org/r/20170913213152.754334077@linutronix.de
---
 kernel/irq/manage.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

(limited to 'kernel/irq/manage.c')

diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 0e8b48315f3c..e667912d0e9c 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -519,7 +519,7 @@ void __enable_irq(struct irq_desc *desc)
 		 * time. If it was already started up, then irq_startup()
 		 * will invoke irq_enable() under the hood.
 		 */
-		irq_startup(desc, IRQ_RESEND, IRQ_START_COND);
+		irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE);
 		break;
 	}
 	default:
@@ -1325,6 +1325,21 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
 				goto out_unlock;
 		}
 
+		/*
+		 * Activate the interrupt. That activation must happen
+		 * independently of IRQ_NOAUTOEN. request_irq() can fail
+		 * and the callers are supposed to handle
+		 * that. enable_irq() of an interrupt requested with
+		 * IRQ_NOAUTOEN is not supposed to fail. The activation
+		 * keeps it in shutdown mode, it merily associates
+		 * resources if necessary and if that's not possible it
+		 * fails. Interrupts which are in managed shutdown mode
+		 * will simply ignore that activation request.
+		 */
+		ret = irq_activate(desc);
+		if (ret)
+			goto out_unlock;
+
 		desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \
 				  IRQS_ONESHOT | IRQS_WAITING);
 		irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS);
-- 
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