From: Ayaz Abdulla <aabdulla@nvidia.com>
Date: Thu, 12 Jun 2008 00:20:18 +0000 (+0000)
Subject: forcedeth: msi interrupts
X-Git-Tag: v2.6.25.7~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8af4f53dd282f803621c9c5d928e17eed65e0d76;p=thirdparty%2Fkernel%2Fstable.git

forcedeth: msi interrupts

commit 4db0ee176e256444695ee2d7b004552e82fec987 upstream

Add a workaround for lost MSI interrupts.  There is a race condition in
the HW in which future interrupts could be missed.  The workaround is to
toggle the MSI irq mask.

Added cleanup based on comments from Andrew Morton.

Signed-off-by: Ayaz Abdulla <aabdulla@nvidia.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/net/forcedeth.c b/drivers/net/forcedeth.c
index 9f088a47d8b14..8e877e7665815 100644
--- a/drivers/net/forcedeth.c
+++ b/drivers/net/forcedeth.c
@@ -3111,6 +3111,20 @@ static void nv_link_irq(struct net_device *dev)
 	dprintk(KERN_DEBUG "%s: link change notification done.\n", dev->name);
 }
 
+static void nv_msi_workaround(struct fe_priv *np)
+{
+
+	/* Need to toggle the msi irq mask within the ethernet device,
+	 * otherwise, future interrupts will not be detected.
+	 */
+	if (np->msi_flags & NV_MSI_ENABLED) {
+		u8 __iomem *base = np->base;
+
+		writel(0, base + NvRegMSIIrqMask);
+		writel(NVREG_MSI_VECTOR_0_ENABLED, base + NvRegMSIIrqMask);
+	}
+}
+
 static irqreturn_t nv_nic_irq(int foo, void *data)
 {
 	struct net_device *dev = (struct net_device *) data;
@@ -3133,6 +3147,8 @@ static irqreturn_t nv_nic_irq(int foo, void *data)
 		if (!(events & np->irqmask))
 			break;
 
+		nv_msi_workaround(np);
+
 		spin_lock(&np->lock);
 		nv_tx_done(dev);
 		spin_unlock(&np->lock);
@@ -3248,6 +3264,8 @@ static irqreturn_t nv_nic_irq_optimized(int foo, void *data)
 		if (!(events & np->irqmask))
 			break;
 
+		nv_msi_workaround(np);
+
 		spin_lock(&np->lock);
 		nv_tx_done_optimized(dev, TX_WORK_PER_LOOP);
 		spin_unlock(&np->lock);
@@ -3588,6 +3606,8 @@ static irqreturn_t nv_nic_irq_test(int foo, void *data)
 	if (!(events & NVREG_IRQ_TIMER))
 		return IRQ_RETVAL(0);
 
+	nv_msi_workaround(np);
+
 	spin_lock(&np->lock);
 	np->intr_test = 1;
 	spin_unlock(&np->lock);