Commit 67347eba authored May 10, 2011 by Milton Miller Committed by Benjamin Herrenschmidt May 19, 2011

powerpc/mpc62xx_pic: Fix get_irq handling of NO_IRQ



If none of irq category bits were set mpc52xx_get_irq() would pass
NO_IRQ_IGNORE (-1) to irq_linear_revmap, which does an unsigned compare
and declares the interrupt above the linear map range.  It then punts
to irq_find_mapping, which performs a linear search of all irqs,
which will likely miss and only then return NO_IRQ.

If no status bit is set, then we should return NO_IRQ directly.
The interrupt should not be suppressed from spurious counting, in fact
that is the definition of supurious.

Signed-off-by: Milton Miller <miltonm@bga.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

parent c42385cd

arch/powerpc/platforms/52xx/mpc52xx_pic.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -486,7 +486,7 @@ void __init mpc52xx_init_irq(void)
		unsigned int mpc52xx_get_irq(void)
		{
		u32 status;
		int irq = NO_IRQ_IGNORE;
		int irq;

		status = in_be32(&intr->enc_status);
		if (status & 0x00000400) { /* critical */
		@@ -509,6 +509,8 @@ unsigned int mpc52xx_get_irq(void)
		} else {
		irq \|= (MPC52xx_IRQ_L1_PERP << MPC52xx_IRQ_L1_OFFSET);
		}
		} else {
		return NO_IRQ;
		}

		return irq_linear_revmap(mpc52xx_irqhost, irq);