Hi all,
On Wed, 16 Aug 2017 09:51:28 +1000 Stephen Rothwell <s...@canb.auug.org.au>
wrote:
>
> Today's linux-next merge of the pci tree got a conflict in:
>
> drivers/pci/probe.c
>
> between commit:
>
> a99b646afa8a ("PCI: Disable PCIe Relaxed Ordering if unsupported")
>
> from the net tree and commit:
>
> 62ce94a7a5a5 ("PCI: Mark Broadcom HT2100 Root Port Extended Tags as broken")
>
> from the pci tree.
>
> I fixed it up (see below) and can carry the fix as necessary. This
> is now fixed as far as linux-next is concerned, but any non trivial
> conflicts should be mentioned to your upstream maintainer when your tree
> is submitted for merging. You may also want to consider cooperating
> with the maintainer of the conflicting tree to minimise any particularly
> complex conflicts.
>
> --
> Cheers,
> Stephen Rothwell
>
> diff --cc drivers/pci/probe.c
> index e6a917b4acd3,d11fede6bd53..000000000000
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@@ -1751,67 -1753,51 +1753,94 @@@ int pci_configure_extended_tags(struct
> int ret;
>
> if (!pci_is_pcie(dev))
> - return;
> + return 0;
>
> - ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &dev_cap);
> + ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
> if (ret)
> - return;
> + return 0;
> +
> + if (!(cap & PCI_EXP_DEVCAP_EXT_TAG))
> + return 0;
> +
> + ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl);
> + if (ret)
> + return 0;
> +
> + host = pci_find_host_bridge(dev->bus);
> + if (!host)
> + return 0;
> +
> + /*
> + * If some device in the hierarchy doesn't handle Extended Tags
> + * correctly, make sure they're disabled.
> + */
> + if (host->no_ext_tags) {
> + if (ctl & PCI_EXP_DEVCTL_EXT_TAG) {
> + dev_info(&dev->dev, "disabling Extended Tags\n");
> + pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
> + PCI_EXP_DEVCTL_EXT_TAG);
> + }
> + return 0;
> + }
>
> - if (dev_cap & PCI_EXP_DEVCAP_EXT_TAG)
> + if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) {
> + dev_info(&dev->dev, "enabling Extended Tags\n");
> pcie_capability_set_word(dev, PCI_EXP_DEVCTL,
> PCI_EXP_DEVCTL_EXT_TAG);
> + }
> + return 0;
> }
>
> +/**
> + * pcie_relaxed_ordering_enabled - Probe for PCIe relaxed ordering enable
> + * @dev: PCI device to query
> + *
> + * Returns true if the device has enabled relaxed ordering attribute.
> + */
> +bool pcie_relaxed_ordering_enabled(struct pci_dev *dev)
> +{
> + u16 v;
> +
> + pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &v);
> +
> + return !!(v & PCI_EXP_DEVCTL_RELAX_EN);
> +}
> +EXPORT_SYMBOL(pcie_relaxed_ordering_enabled);
> +
> +static void pci_configure_relaxed_ordering(struct pci_dev *dev)
> +{
> + struct pci_dev *root;
> +
> + /* PCI_EXP_DEVICE_RELAX_EN is RsvdP in VFs */
> + if (dev->is_virtfn)
> + return;
> +
> + if (!pcie_relaxed_ordering_enabled(dev))
> + return;
> +
> + /*
> + * For now, we only deal with Relaxed Ordering issues with Root
> + * Ports. Peer-to-Peer DMA is another can of worms.
> + */
> + root = pci_find_pcie_root_port(dev);
> + if (!root)
> + return;
> +
> + if (root->dev_flags & PCI_DEV_FLAGS_NO_RELAXED_ORDERING) {
> + pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
> + PCI_EXP_DEVCTL_RELAX_EN);
> + dev_info(&dev->dev, "Disable Relaxed Ordering because the Root
> Port didn't support it\n");
> + }
> +}
> +
> static void pci_configure_device(struct pci_dev *dev)
> {
> struct hotplug_params hpp;
> int ret;
>
> pci_configure_mps(dev);
> - pci_configure_extended_tags(dev);
> + pci_configure_extended_tags(dev, NULL);
> + pci_configure_relaxed_ordering(dev);
>
> memset(&hpp, 0, sizeof(hpp));
> ret = pci_get_hp_params(dev, &hpp);
Just a reminder that this conflict still exists.
--
Cheers,
Stephen Rothwell
