From ba1826e5eced176cc9ec0033ad8ee0f1cd5ad2e4 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 5 Jul 2006 15:36:15 +1000 Subject: [PATCH] [PATCH] powerpc: Fix loss of interrupts with MPIC With the new interrupt rework, an interrupt "host" map() callback can be called after the interrupt is already active. It's called again for an already mapped interrupt to allow changing the trigger setup, and currently this is not guarded with a test of wether the interrupt is requested or not. I plan to change some of this logic to be a bit less lenient against random reconfiguring of live interrupts but just not yet. The ported MPIC driver has a bug where when that happens, it will mask the interrupt. This changes it to preserve the previous masking of the interrupt instead. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Linus Torvalds --- arch/powerpc/sysdev/mpic.c | 39 ++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c index 7d31d7cc39..9cecebaa03 100644 --- a/arch/powerpc/sysdev/mpic.c +++ b/arch/powerpc/sysdev/mpic.c @@ -405,20 +405,22 @@ static void mpic_unmask_irq(unsigned int irq) unsigned int loops = 100000; struct mpic *mpic = mpic_from_irq(irq); unsigned int src = mpic_irq_to_hw(irq); + unsigned long flags; DBG("%p: %s: enable_irq: %d (src %d)\n", mpic, mpic->name, irq, src); + spin_lock_irqsave(&mpic_lock, flags); mpic_irq_write(src, MPIC_IRQ_VECTOR_PRI, mpic_irq_read(src, MPIC_IRQ_VECTOR_PRI) & ~MPIC_VECPRI_MASK); - /* make sure mask gets to controller before we return to user */ do { if (!loops--) { printk(KERN_ERR "mpic_enable_irq timeout\n"); break; } - } while(mpic_irq_read(src, MPIC_IRQ_VECTOR_PRI) & MPIC_VECPRI_MASK); + } while(mpic_irq_read(src, MPIC_IRQ_VECTOR_PRI) & MPIC_VECPRI_MASK); + spin_unlock_irqrestore(&mpic_lock, flags); } static void mpic_mask_irq(unsigned int irq) @@ -426,9 +428,11 @@ static void mpic_mask_irq(unsigned int irq) unsigned int loops = 100000; struct mpic *mpic = mpic_from_irq(irq); unsigned int src = mpic_irq_to_hw(irq); + unsigned long flags; DBG("%s: disable_irq: %d (src %d)\n", mpic->name, irq, src); + spin_lock_irqsave(&mpic_lock, flags); mpic_irq_write(src, MPIC_IRQ_VECTOR_PRI, mpic_irq_read(src, MPIC_IRQ_VECTOR_PRI) | MPIC_VECPRI_MASK); @@ -440,6 +444,7 @@ static void mpic_mask_irq(unsigned int irq) break; } } while(!(mpic_irq_read(src, MPIC_IRQ_VECTOR_PRI) & MPIC_VECPRI_MASK)); + spin_unlock_irqrestore(&mpic_lock, flags); } static void mpic_end_irq(unsigned int irq) @@ -624,9 +629,10 @@ static int mpic_host_map(struct irq_host *h, unsigned int virq, struct irq_desc *desc = get_irq_desc(virq); struct irq_chip *chip; struct mpic *mpic = h->host_data; - unsigned int vecpri = MPIC_VECPRI_SENSE_LEVEL | + u32 v, vecpri = MPIC_VECPRI_SENSE_LEVEL | MPIC_VECPRI_POLARITY_NEGATIVE; int level; + unsigned long iflags; pr_debug("mpic: map virq %d, hwirq 0x%lx, flags: 0x%x\n", virq, hw, flags); @@ -668,11 +674,21 @@ static int mpic_host_map(struct irq_host *h, unsigned int virq, } #endif - /* Reconfigure irq */ - vecpri |= MPIC_VECPRI_MASK | hw | (8 << MPIC_VECPRI_PRIORITY_SHIFT); - mpic_irq_write(hw, MPIC_IRQ_VECTOR_PRI, vecpri); - - pr_debug("mpic: mapping as IRQ\n"); + /* Reconfigure irq. We must preserve the mask bit as we can be called + * while the interrupt is still active (This may change in the future + * but for now, it is the case). + */ + spin_lock_irqsave(&mpic_lock, iflags); + v = mpic_irq_read(hw, MPIC_IRQ_VECTOR_PRI); + vecpri = (v & + ~(MPIC_VECPRI_POLARITY_MASK | MPIC_VECPRI_SENSE_MASK)) | + vecpri; + if (vecpri != v) + mpic_irq_write(hw, MPIC_IRQ_VECTOR_PRI, vecpri); + spin_unlock_irqrestore(&mpic_lock, iflags); + + pr_debug("mpic: mapping as IRQ, vecpri = 0x%08x (was 0x%08x)\n", + vecpri, v); set_irq_chip_data(virq, mpic); set_irq_chip_and_handler(virq, chip, handle_fasteoi_irq); @@ -904,8 +920,8 @@ void __init mpic_init(struct mpic *mpic) /* do senses munging */ if (mpic->senses && i < mpic->senses_count) - vecpri = mpic_flags_to_vecpri(mpic->senses[i], - &level); + vecpri |= mpic_flags_to_vecpri(mpic->senses[i], + &level); else vecpri |= MPIC_VECPRI_SENSE_LEVEL; @@ -955,14 +971,17 @@ void __init mpic_set_clk_ratio(struct mpic *mpic, u32 clock_ratio) void __init mpic_set_serial_int(struct mpic *mpic, int enable) { + unsigned long flags; u32 v; + spin_lock_irqsave(&mpic_lock, flags); v = mpic_read(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1); if (enable) v |= MPIC_GREG_GLOBAL_CONF_1_SIE; else v &= ~MPIC_GREG_GLOBAL_CONF_1_SIE; mpic_write(mpic->gregs, MPIC_GREG_GLOBAL_CONF_1, v); + spin_unlock_irqrestore(&mpic_lock, flags); } void mpic_irq_set_priority(unsigned int irq, unsigned int pri) -- 2.39.5