diff options
| author | Asai Thambi S P <asamymuthupa@micron.com> | 2014-03-13 18:45:15 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2014-04-22 19:48:52 -0600 |
| commit | d1e714db8129a1d3670e449b87719c78e2c76f9f (patch) | |
| tree | 34ed981357620ab4d648edc4d680d85f079e2a51 /drivers | |
| parent | af5ded8ccf21627f9614afc03b356712666ed225 (diff) | |
mtip32xx: Fix ERO and NoSnoop values in PCIe upstream on AMD systems
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@micron.com>
Signed-off-by: Sam Bradshaw <sbradshaw@micron.com>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/block/mtip32xx/mtip32xx.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c index 27641bc83962..fb624469d0ee 100644 --- a/drivers/block/mtip32xx/mtip32xx.c +++ b/drivers/block/mtip32xx/mtip32xx.c @@ -4483,6 +4483,57 @@ 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. * @@ -4634,6 +4685,8 @@ static int mtip_pci_probe(struct pci_dev *pdev, goto msi_initialize_err; } + mtip_fix_ero_nosnoop(dd, pdev); + /* Initialize the block layer. */ rv = mtip_block_initialize(dd); if (rv < 0) { |