Messages in this thread Patch in this message | | | Subject | Re: AMD 8131 and MSI quirk | From | Kristen Accardi <> | Date | Tue, 14 Feb 2006 14:06:19 -0800 |
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On Tue, 2006-02-14 at 23:21 +0200, Michael S. Tsirkin wrote: > Quoting Kristen Accardi <kristen.c.accardi@intel.com>: > > > It turns out AMD 8131 quirk only affects MSI for devices behind the 8131 > > > bridge. Handle this by adding a flags field in pci_bus, inherited from > > > parent to child. > > > > It seems like we have a way to turn of msi already (the no_msi bit in > > the pci_dev structure). Does it make sense to just have the child bus > > pci_dev structure inherit the no_msi bit from the parent's pci_dev > > structure when doing an allocation, or does that unnecessarily remove > > the msi capability for devices that may not need it? > > > > Kristen > > This bit is already used to mean that msi is disabled for a specific device, > which appears to be a PCI Express to PCI bridge (PCI_DEVICE_ID_INTEL_PXH). So > it seems that disabling MSI for child devices as well might break things (i.e. > disable msi unnecessarily). > Working for Intel, I guess you would know about the PCI_DEVICE_ID_INTEL_PXH > best: what do you say? > > In my opinion, it is cleaner to separate the two concepts: suppress msi > for child devices versus suppress it for the specific device. > > Right? >
I was thinking something along these lines might work for you. I think it does the same thing as the other patch, without needing to add extra flags to pci_bus. I guess the assumption I made was that if msi is turned off for a bridge, then all devices under the bridge may not use msi.
--- drivers/pci/msi.c | 2 +- drivers/pci/probe.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-)
--- linux-dock-mm.orig/drivers/pci/msi.c +++ linux-dock-mm/drivers/pci/msi.c @@ -701,7 +701,7 @@ int pci_enable_msi(struct pci_dev* dev) if (!pci_msi_enable || !dev) return status; - if (dev->no_msi) + if (dev->no_msi || dev->bus->self->no_msi) return status; temp = dev->irq; --- linux-dock-mm.orig/drivers/pci/probe.c +++ linux-dock-mm/drivers/pci/probe.c @@ -344,6 +344,7 @@ pci_alloc_child_bus(struct pci_bus *pare return NULL; child->self = bridge; + child->self->no_msi = parent->self->no_msi; child->parent = parent; child->ops = parent->ops; child->sysdata = parent->sysdata; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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