Dave,
Commit Log:
        Patch to enable tg3 to use MSI instead of line based interrupts.
        Tested on ia64 with BCM5701 (PCI mode) and it works fine there.

Signed-off-by: Grant Grundler ([EMAIL PROTECTED])


I thought at first I should add a runtime driver parameter like mthca
(Infiniband) driver does (e.g. msi=1). But I would prefer if tg3 left
(a new) TG3_FLG2_USE_MSI flag unset for bcm5xxx chips with MSI bugs.

And if the platform claims MSI support but doesn't work right,
then pci_enable_msi() will cause problems with any device whose
driver attempts to enable MSI. A kernel "command line" parameter
could turn off MSI and/or MSIX support for all devices on that platform.
(I know this is going to be a problem on parisc...I'll propose something
more concrete when I get there).

BTW, adding MSI support will enable tg3 to drop one MMIO read
in tg3_interrupt. Once this patch is accepted/rejected I'll work
on a tg3_msi_interrupt() routine and investigate status_tag implementation.

thanks,
grant


===== drivers/net/tg3.c 1.222 vs edited =====
--- 1.222/drivers/net/tg3.c     2004-11-15 15:53:08 -08:00
+++ edited/drivers/net/tg3.c    2005-01-15 11:43:51 -08:00
@@ -5679,10 +5679,19 @@
        if (err)
                return err;
 
-       err = request_irq(dev->irq, tg3_interrupt,
-                         SA_SHIRQ, dev->name, dev);
+       if (pci_enable_msi(tp->pdev))
+               printk(KERN_WARNING PFX "MSI NOT enabled for %s\n",
+                               tp->pdev->slot_name);
+       else {
+               tw32(MSGINT_MODE, MSGINT_MODE_ENABLE);
+               printk(KERN_INFO PFX "MSI enabled on %s\n",
+                               tp->pdev->slot_name);
+       }
+
+       err = request_irq(dev->irq, tg3_interrupt, SA_SHIRQ, dev->name, dev);
 
        if (err) {
+               pci_disable_msi(tp->pdev);
                tg3_free_consistent(tp);
                return err;
        }
@@ -5713,6 +5722,7 @@
 
        if (err) {
                free_irq(dev->irq, dev);
+               pci_disable_msi(tp->pdev);
                tg3_free_consistent(tp);
                return err;
        }
@@ -5988,6 +5998,7 @@
        spin_unlock_irq(&tp->lock);
 
        free_irq(dev->irq, dev);
+       pci_disable_msi(tp->pdev);
 
        memcpy(&tp->net_stats_prev, tg3_get_stats(tp->dev),
               sizeof(tp->net_stats_prev));
-
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