ahci: don't enable port irq before handler is registered

[deliverable/linux.git] / drivers / ata / libahci.c

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 633159b5152aaa03de0a4fa051d7f2c14dfa3edf..d38c40fe4ddbfeace9bb1460505aac4add9d23f1 100644 (file)
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1919,7 +1919,17 @@ static void ahci_pmp_attach(struct ata_port *ap)
        ahci_enable_fbs(ap);
 
        pp->intr_mask |= PORT_IRQ_BAD_PMP;
-       writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+
+       /*
+        * We must not change the port interrupt mask register if the
+        * port is marked frozen, the value in pp->intr_mask will be
+        * restored later when the port is thawed.
+        *
+        * Note that during initialization, the port is marked as
+        * frozen since the irq handler is not yet registered.
+        */
+       if (!(ap->pflags & ATA_PFLAG_FROZEN))
+               writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
 }
 
 static void ahci_pmp_detach(struct ata_port *ap)
@@ -1935,7 +1945,10 @@ static void ahci_pmp_detach(struct ata_port *ap)
        writel(cmd, port_mmio + PORT_CMD);
 
        pp->intr_mask &= ~PORT_IRQ_BAD_PMP;
-       writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+
+       /* see comment above in ahci_pmp_attach() */
+       if (!(ap->pflags & ATA_PFLAG_FROZEN))
+               writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
 }
 
 int ahci_port_resume(struct ata_port *ap)