diff options
Diffstat (limited to 'drivers/ata/ahci.c')
| -rw-r--r-- | drivers/ata/ahci.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 6a4a2a25d97..5e6468a7ca4 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -1777,7 +1777,7 @@ static irqreturn_t ahci_interrupt(int irq, void *dev_instance) struct ahci_host_priv *hpriv; unsigned int i, handled = 0; void __iomem *mmio; - u32 irq_stat, irq_ack = 0; + u32 irq_stat, irq_masked; VPRINTK("ENTER\n"); @@ -1786,16 +1786,17 @@ static irqreturn_t ahci_interrupt(int irq, void *dev_instance) /* sigh. 0xffffffff is a valid return from h/w */ irq_stat = readl(mmio + HOST_IRQ_STAT); - irq_stat &= hpriv->port_map; if (!irq_stat) return IRQ_NONE; + irq_masked = irq_stat & hpriv->port_map; + spin_lock(&host->lock); for (i = 0; i < host->n_ports; i++) { struct ata_port *ap; - if (!(irq_stat & (1 << i))) + if (!(irq_masked & (1 << i))) continue; ap = host->ports[i]; @@ -1809,14 +1810,20 @@ static irqreturn_t ahci_interrupt(int irq, void *dev_instance) "interrupt on disabled port %u\n", i); } - irq_ack |= (1 << i); - } - - if (irq_ack) { - writel(irq_ack, mmio + HOST_IRQ_STAT); handled = 1; } + /* HOST_IRQ_STAT behaves as level triggered latch meaning that + * it should be cleared after all the port events are cleared; + * otherwise, it will raise a spurious interrupt after each + * valid one. Please read section 10.6.2 of ahci 1.1 for more + * information. + * + * Also, use the unmasked value to clear interrupt as spurious + * pending event on a dummy port might cause screaming IRQ. + */ + writel(irq_stat, mmio + HOST_IRQ_STAT); + spin_unlock(&host->lock); VPRINTK("EXIT\n"); |