Grant,
The latest Broadcom errata for the 57XX controllers indicates that MSI
isn't supported on most of their shipping controllers. There is a problem
where interrupts aren't masked when MSI is used.
Dave
> 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 (grundler@xxxxxxxxxxxxxxxx)
>
>
> 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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