Commit ea0c62f7 authored Jun 28, 2008 by Tejun Heo Committed by Jeff Garzik Jul 04, 2008

ahci: always clear all bits in irq_stat

Some AHCI controllers (ICH7 was reported) set pending bit in
HOST_IRQ_STAT for non-existent ports and when it's not cleared falls
into IRQ storm.  Always clear full irq_stat instead of only the bits
that are handled.  As nothing changes for recognized ports, the risk
of breaking things is pretty low.

Reported and verified by Philipp Thomas in the following suse
bugzilla.

https://bugzilla.novell.com/attachment.cgi?id=215692



Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Philipp Thomas <pth@novell.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

parent 464b3286

drivers/ata/ahci.c

+3 −6

Original line number	Diff line number	Diff line
		@@ -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;

		VPRINTK("ENTER\n");

		@@ -1809,14 +1809,11 @@ 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;
		}

		writel(irq_stat, mmio + HOST_IRQ_STAT);

		spin_unlock(&host->lock);

		VPRINTK("EXIT\n");

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