releases/2.6.18.2/sky2-msi-test-race-and-message.patch

From stable-bounces@linux.kernel.org Thu Oct 12 15:38:46 2006
Date: Thu, 12 Oct 2006 15:38:11 -0700
From: Stephen Hemminger <shemminger@osdl.org>
To: stable@kernel.org
Message-ID: <20061012153811.09790730@freekitty>
Mime-Version: 1.0
Subject: sky2: MSI test race and message
Content-Type: text/plain; charset="us-ascii"

From: Stephen Hemminger <shemminger@osdl.org>

Make sure and do PCI reads after writes in the MSI test setup code.

Some motherboards don't implement MSI correctly. The driver handles this
but the warning is too verbose and overly cautious.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>

---
 drivers/net/sky2.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

--- linux-2.6.18.1.orig/drivers/net/sky2.c
+++ linux-2.6.18.1/drivers/net/sky2.c
@@ -3208,6 +3208,8 @@ static int __devinit sky2_test_msi(struc
 	struct pci_dev *pdev = hw->pdev;
 	int err;
 
+	init_waitqueue_head (&hw->msi_wait);
+
 	sky2_write32(hw, B0_IMSK, Y2_IS_IRQ_SW);
 
 	err = request_irq(pdev->irq, sky2_test_intr, IRQF_SHARED, DRV_NAME, hw);
@@ -3217,18 +3219,15 @@ static int __devinit sky2_test_msi(struc
 		return err;
 	}
 
-	init_waitqueue_head (&hw->msi_wait);
-
 	sky2_write8(hw, B0_CTST, CS_ST_SW_IRQ);
-	wmb();
+	sky2_read8(hw, B0_CTST);
 
 	wait_event_timeout(hw->msi_wait, hw->msi_detected, HZ/10);
 
 	if (!hw->msi_detected) {
 		/* MSI test failed, go back to INTx mode */
-		printk(KERN_WARNING PFX "%s: No interrupt was generated using MSI, "
-		       "switching to INTx mode. Please report this failure to "
-		       "the PCI maintainer and include system chipset information.\n",
+		printk(KERN_INFO PFX "%s: No interrupt generated using MSI, "
+		       "switching to INTx mode.\n",
 		       pci_name(pdev));
 
 		err = -EOPNOTSUPP;
@@ -3236,6 +3235,7 @@ static int __devinit sky2_test_msi(struc
 	}
 
 	sky2_write32(hw, B0_IMSK, 0);
+	sky2_read32(hw, B0_IMSK);
 
 	free_irq(pdev->irq, hw);