diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/drm_pci.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c index 13f3d936472..5320364582c 100644 --- a/drivers/gpu/drm/drm_pci.c +++ b/drivers/gpu/drm/drm_pci.c @@ -465,3 +465,52 @@ void drm_pci_exit(struct drm_driver *driver, struct pci_driver *pdriver) DRM_INFO("Module unloaded\n"); } EXPORT_SYMBOL(drm_pci_exit); + +int drm_pcie_get_speed_cap_mask(struct drm_device *dev, u32 *mask) +{ + struct pci_dev *root; + int pos; + u32 lnkcap, lnkcap2; + + *mask = 0; + if (!dev->pdev) + return -EINVAL; + + if (!pci_is_pcie(dev->pdev)) + return -EINVAL; + + root = dev->pdev->bus->self; + + pos = pci_pcie_cap(root); + if (!pos) + return -EINVAL; + + /* we've been informed via and serverworks don't make the cut */ + if (root->vendor == PCI_VENDOR_ID_VIA || + root->vendor == PCI_VENDOR_ID_SERVERWORKS) + return -EINVAL; + + pci_read_config_dword(root, pos + PCI_EXP_LNKCAP, &lnkcap); + pci_read_config_dword(root, pos + PCI_EXP_LNKCAP2, &lnkcap2); + + lnkcap &= PCI_EXP_LNKCAP_SLS; + lnkcap2 &= 0xfe; + + if (lnkcap2) { /* PCIE GEN 3.0 */ + if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB) + *mask |= DRM_PCIE_SPEED_25; + if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB) + *mask |= DRM_PCIE_SPEED_50; + if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB) + *mask |= DRM_PCIE_SPEED_80; + } else { + if (lnkcap & 1) + *mask |= DRM_PCIE_SPEED_25; + if (lnkcap & 2) + *mask |= DRM_PCIE_SPEED_50; + } + + DRM_INFO("probing gen 2 caps for device %x:%x = %x/%x\n", root->vendor, root->device, lnkcap, lnkcap2); + return 0; +} +EXPORT_SYMBOL(drm_pcie_get_speed_cap_mask); |