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Date: Thu, 29 Jul 2004 21:33:41 +0200
From: Ingo Molnar <mingo@elte.hu>
To: Scott Wood <scott@timesys.com>
Cc: linux-kernel@vger.kernel.org, "La Monte H.P. Yarroll" <piggy@timesys.com>,
       Manas Saksena <manas.saksena@timesys.com>
Subject: Re: [patch] IRQ threads
Message-ID: <20040729193341.GA27057@elte.hu>
References: <20040727225040.GA4370@yoda.timesys> <20040728081005.GA20100@elte.hu> <20040728231241.GE6685@yoda.timesys>
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* Scott Wood <scott@timesys.com> wrote:

> > Also, why the enable_irq() change? 
> 
> If you mean the do_startup_irq() change, [...]

i mean the change below - why do irqthreads necessiate it?

	Ingo

@@ -395,7 +402,14 @@ void enable_irq(unsigned int irq)
 			desc->status = status | IRQ_REPLAY;
 			hw_resend_irq(desc->handler,irq);
 		}
-		desc->handler->enable(irq);
+		
+		/* Don't unmask the IRQ if it's in progress, or else you
+		   could re-enter the IRQ handler.  As it is now enabled,
+		   the IRQ will be unmasked when the handler is finished. */
+		
+		if (!(desc->status & (IRQ_INPROGRESS | IRQ_THREADRUNNING |
+		                      IRQ_THREADPENDING)))
+			desc->handler->enable(irq);
 		/* fall-through */
 	}
 	default: