From: Jeremy Kerr Date: Fri, 4 Apr 2008 06:55:28 +0000 (+1100) Subject: [POWERPC] cell: Fix lost interrupts due to fasteoi handler X-Git-Tag: v2.6.26-rc2~16^2~20 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=5711fe900dfef8d9afdbbb6d0f9c9720919d1d66;p=linux-2.6-omap-h63xx.git [POWERPC] cell: Fix lost interrupts due to fasteoi handler We may currently lose interrupts during SPE context switch, as we alter the INT_Route register. Because the IIC uses a per-thread priority status, changing the interrupt routing to a different thread means that the IRQ is no longer masked by the priority status, so we end up with two fasteoi IRQ handlers executing for the one irq_desc. The fasteoi handler doesn't handle multiple IRQs, so drops the second one. Fix this by using our own flow handler. This is based on handle_edge_irq, but issues an eoi after IRQs are handled, and doesn't do any mask/unmasking. Signed-off-by: Jeremy Kerr --- diff --git a/arch/powerpc/platforms/cell/interrupt.c b/arch/powerpc/platforms/cell/interrupt.c index 04f74f9f9ab..5bf7df14602 100644 --- a/arch/powerpc/platforms/cell/interrupt.c +++ b/arch/powerpc/platforms/cell/interrupt.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include @@ -231,6 +232,54 @@ static int iic_host_match(struct irq_host *h, struct device_node *node) "IBM,CBEA-Internal-Interrupt-Controller"); } +extern int noirqdebug; + +static void handle_iic_irq(unsigned int irq, struct irq_desc *desc) +{ + const unsigned int cpu = smp_processor_id(); + + spin_lock(&desc->lock); + + desc->status &= ~(IRQ_REPLAY | IRQ_WAITING); + + /* + * If we're currently running this IRQ, or its disabled, + * we shouldn't process the IRQ. Mark it pending, handle + * the necessary masking and go out + */ + if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) || + !desc->action)) { + desc->status |= IRQ_PENDING; + goto out_eoi; + } + + kstat_cpu(cpu).irqs[irq]++; + + /* Mark the IRQ currently in progress.*/ + desc->status |= IRQ_INPROGRESS; + + do { + struct irqaction *action = desc->action; + irqreturn_t action_ret; + + if (unlikely(!action)) + goto out_eoi; + + desc->status &= ~IRQ_PENDING; + spin_unlock(&desc->lock); + action_ret = handle_IRQ_event(irq, action); + if (!noirqdebug) + note_interrupt(irq, desc, action_ret); + spin_lock(&desc->lock); + + } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING); + + desc->status &= ~IRQ_INPROGRESS; +out_eoi: + desc->chip->eoi(irq); + spin_unlock(&desc->lock); +} + static int iic_host_map(struct irq_host *h, unsigned int virq, irq_hw_number_t hw) { @@ -240,10 +289,10 @@ static int iic_host_map(struct irq_host *h, unsigned int virq, break; case IIC_IRQ_TYPE_IOEXC: set_irq_chip_and_handler(virq, &iic_ioexc_chip, - handle_fasteoi_irq); + handle_iic_irq); break; default: - set_irq_chip_and_handler(virq, &iic_chip, handle_fasteoi_irq); + set_irq_chip_and_handler(virq, &iic_chip, handle_iic_irq); } return 0; }