From: Milton Miller Date: Tue, 10 May 2011 19:30:18 +0000 (+0000) Subject: powerpc/mpc62xx_pic: Fix get_irq handling of NO_IRQ X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=67347eba156d64150be73c9f5797342a66b123d9;p=linux-beck.git 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 Acked-by: Grant Likely Signed-off-by: Benjamin Herrenschmidt --- diff --git a/arch/powerpc/platforms/52xx/mpc52xx_pic.c b/arch/powerpc/platforms/52xx/mpc52xx_pic.c index bb611819b832..1a9a49570579 100644 --- a/arch/powerpc/platforms/52xx/mpc52xx_pic.c +++ b/arch/powerpc/platforms/52xx/mpc52xx_pic.c @@ -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);