This is a note to let you know that I've just added the patch titled mtip32xx: Fix ERO and NoSnoop values in PCIe upstream on AMD systems to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mtip32xx-fix-ero-and-nosnoop-values-in-pcie-upstream-on-amd-systems.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From d1e714db8129a1d3670e449b87719c78e2c76f9f Mon Sep 17 00:00:00 2001 From: Asai Thambi S P <asamymuthupa@xxxxxxxxxx> Date: Thu, 13 Mar 2014 18:45:15 -0700 Subject: mtip32xx: Fix ERO and NoSnoop values in PCIe upstream on AMD systems From: Asai Thambi S P <asamymuthupa@xxxxxxxxxx> commit d1e714db8129a1d3670e449b87719c78e2c76f9f upstream. A hardware quirk in P320h/P420m interfere with PCIe transactions on some AMD chipsets, making P320h/P420m unusable. This workaround is to disable ERO and NoSnoop bits in the parent and root complex for normal functioning of these devices NOTE: This workaround is specific to AMD chipset with a PCIe upstream device with device id 0x5aXX Signed-off-by: Asai Thambi S P <asamymuthupa@xxxxxxxxxx> Signed-off-by: Sam Bradshaw <sbradshaw@xxxxxxxxxx> Signed-off-by: Jens Axboe <axboe@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/block/mtip32xx/mtip32xx.c | 53 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) --- a/drivers/block/mtip32xx/mtip32xx.c +++ b/drivers/block/mtip32xx/mtip32xx.c @@ -4479,6 +4479,57 @@ static DEFINE_HANDLER(5); static DEFINE_HANDLER(6); static DEFINE_HANDLER(7); +static void mtip_disable_link_opts(struct driver_data *dd, struct pci_dev *pdev) +{ + int pos; + unsigned short pcie_dev_ctrl; + + pos = pci_find_capability(pdev, PCI_CAP_ID_EXP); + if (pos) { + pci_read_config_word(pdev, + pos + PCI_EXP_DEVCTL, + &pcie_dev_ctrl); + if (pcie_dev_ctrl & (1 << 11) || + pcie_dev_ctrl & (1 << 4)) { + dev_info(&dd->pdev->dev, + "Disabling ERO/No-Snoop on bridge device %04x:%04x\n", + pdev->vendor, pdev->device); + pcie_dev_ctrl &= ~(PCI_EXP_DEVCTL_NOSNOOP_EN | + PCI_EXP_DEVCTL_RELAX_EN); + pci_write_config_word(pdev, + pos + PCI_EXP_DEVCTL, + pcie_dev_ctrl); + } + } +} + +static void mtip_fix_ero_nosnoop(struct driver_data *dd, struct pci_dev *pdev) +{ + /* + * This workaround is specific to AMD/ATI chipset with a PCI upstream + * device with device id 0x5aXX + */ + if (pdev->bus && pdev->bus->self) { + if (pdev->bus->self->vendor == PCI_VENDOR_ID_ATI && + ((pdev->bus->self->device & 0xff00) == 0x5a00)) { + mtip_disable_link_opts(dd, pdev->bus->self); + } else { + /* Check further up the topology */ + struct pci_dev *parent_dev = pdev->bus->self; + if (parent_dev->bus && + parent_dev->bus->parent && + parent_dev->bus->parent->self && + parent_dev->bus->parent->self->vendor == + PCI_VENDOR_ID_ATI && + (parent_dev->bus->parent->self->device & + 0xff00) == 0x5a00) { + mtip_disable_link_opts(dd, + parent_dev->bus->parent->self); + } + } + } +} + /* * Called for each supported PCI device detected. * @@ -4630,6 +4681,8 @@ static int mtip_pci_probe(struct pci_dev goto block_initialize_err; } + mtip_fix_ero_nosnoop(dd, pdev); + /* Initialize the block layer. */ rv = mtip_block_initialize(dd); if (rv < 0) { Patches currently in stable-queue which might be from asamymuthupa@xxxxxxxxxx are queue-3.14/mtip32xx-increase-timeout-for-standby-immediate-command.patch queue-3.14/mtip32xx-remove-dfs_parent-after-pci-unregister.patch queue-3.14/mtip32xx-fix-ero-and-nosnoop-values-in-pcie-upstream-on-amd-systems.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html