Re: [PATCH] quirk: Enable MSI Mapping on HT1000

From: Eric W. Biederman
Date: Tue Nov 27 2007 - 08:01:46 EST


Sébastien Dugué <sebastien.dugue@xxxxxxxx> writes:

> From: Sebastien Dugue <sebastien.dugue@xxxxxxxx>
>
> Add a quirk to enable the MSI mapping capability on HyperTransport
> bridges.
>
> Wire Broadcom's HT1000 to use the quirk.
>
> This patch applies cleanly on 2.6.24-rc3-mm1 and was tested on 2.6.24-rc3
> (sorry, but 2.6.24-rc3-mm1 would not boot on my box).
>
> I also have been running 2.6.21-rt10 with that patch for quite some
> time now.
>
> Sebastien.

Looks like a sane starting point, and if we know the chipset can
do it preferable to disabling msi on that chipset.

Acked-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>

>
> Signed-off-by: Sebastien Dugue <sebastien.dugue@xxxxxxxx>
> Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
> Cc: Andy Currid <acurrid@xxxxxxxxxx>
> Cc: Peer Chen <pchen@xxxxxxxxxx>
> Cc: Prakash Punnoor <prakash@xxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Michael Chan <mchan@xxxxxxxxxxxx>
>
> ---
> drivers/pci/quirks.c | 27 +++++++++++++++++++++++++++
> 1 file changed, 27 insertions(+)
>
> Index: linux-2.6.24-rc3-mm1/drivers/pci/quirks.c
> ===================================================================
> --- linux-2.6.24-rc3-mm1.orig/drivers/pci/quirks.c
> +++ linux-2.6.24-rc3-mm1/drivers/pci/quirks.c
> @@ -1681,6 +1681,33 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_SE
> PCI_DEVICE_ID_SERVERWORKS_HT1000_PXB,
> quirk_msi_ht_cap);
>
> +
> +/*
> + * Force enable MSI mapping capability on HT bridges
> + */
> +static void __devinit quirk_msi_ht_cap_enable(struct pci_dev *dev)
> +{
> + int pos, ttl = 48;
> +
> + pos = pci_find_ht_capability(dev, HT_CAPTYPE_MSI_MAPPING);
> + while (pos && ttl--) {
> + u8 flags;
> +
> + if (pci_read_config_byte(dev, pos + HT_MSI_FLAGS, &flags) == 0) {
> + printk(KERN_INFO "PCI: Enabling HT MSI Mapping on %s\n",
> + pci_name(dev));
> +
> + pci_write_config_byte(dev, pos + HT_MSI_FLAGS,
> + flags | HT_MSI_FLAGS_ENABLE);
> + }
> + pos = pci_find_next_ht_capability(dev, pos,
> + HT_CAPTYPE_MSI_MAPPING);
> + }
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SERVERWORKS,
> + PCI_DEVICE_ID_SERVERWORKS_HT1000_PXB,
> + quirk_msi_ht_cap_enable);
> +
> /* The nVidia CK804 chipset may have 2 HT MSI mappings.
> * MSI are supported if the MSI capability set in any of these mappings.
> */
-
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