Re: [PATCH] Disable INTx when enabling MSI in forcedeth

[Jeff Garzik <jeff@garzik.org>]

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Linus Torvalds wrote:
> 
> On Tue, 21 Nov 2006, Daniel Barkalow wrote:
>> My nVidia ethernet card doesn't disable its own INTx when MSI is
>> enabled. This causes a steady stream of spurious interrupts that
>> eventually kills my SATA IRQ if MSI is used with forcedeth, which is
>> true by default. Simply disabling the INTx interrupt takes care of it.
>>
>> This is against -stable, and would be suitable once someone who knows the 
>> code verifies that it's correct.
> 
> I _really_ think that we should do this in pci_msi_enable().
> 
> Screw cards that are not PCI-2.3 compliant - just make the rule be that if 
> you use MSI, you _have_ to allow us to set the disable-INTx bit. It's then 
> up to the drivers to decide if they can use MSI or not.
> 
> (Even a number of cards that are not PCI-2.3 may simply not _implement_ 
> the disable-INTx bit, and in that case, they can use MSI if they disable 
> INTx automatically - the ).
> 
> Comments?

I agree.  And it's just a simple matter of remove the PCI-Express 
brackets AFAICS, like in the attached patch (untested).

	Jeff




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diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 9fc9a34..c2828a3 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -255,10 +255,8 @@ static void enable_msi_mode(struct pci_d
 		pci_write_config_word(dev, msi_control_reg(pos), control);
 		dev->msix_enabled = 1;
 	}
-    	if (pci_find_capability(dev, PCI_CAP_ID_EXP)) {
-		/* PCI Express Endpoint device detected */
-		pci_intx(dev, 0);  /* disable intx */
-	}
+
+	pci_intx(dev, 0);  /* disable intx */
 }
 
 void disable_msi_mode(struct pci_dev *dev, int pos, int type)
@@ -276,10 +274,8 @@ void disable_msi_mode(struct pci_dev *de
 		pci_write_config_word(dev, msi_control_reg(pos), control);
 		dev->msix_enabled = 0;
 	}
-    	if (pci_find_capability(dev, PCI_CAP_ID_EXP)) {
-		/* PCI Express Endpoint device detected */
-		pci_intx(dev, 1);  /* enable intx */
-	}
+
+	pci_intx(dev, 1);  /* enable intx */
 }
 
 static int msi_lookup_irq(struct pci_dev *dev, int type)