diff options
Diffstat (limited to 'drivers/gpu/drm/drm_pci.c')
| -rw-r--r-- | drivers/gpu/drm/drm_pci.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c index fcd2a86acd2c..a1fff1179a97 100644 --- a/drivers/gpu/drm/drm_pci.c +++ b/drivers/gpu/drm/drm_pci.c @@ -410,6 +410,26 @@ int drm_pcie_get_speed_cap_mask(struct drm_device *dev, u32 *mask) } EXPORT_SYMBOL(drm_pcie_get_speed_cap_mask); +int drm_pcie_get_max_link_width(struct drm_device *dev, u32 *mlw) +{ + struct pci_dev *root; + u32 lnkcap; + + *mlw = 0; + if (!dev->pdev) + return -EINVAL; + + root = dev->pdev->bus->self; + + pcie_capability_read_dword(root, PCI_EXP_LNKCAP, &lnkcap); + + *mlw = (lnkcap & PCI_EXP_LNKCAP_MLW) >> 4; + + DRM_INFO("probing mlw for device %x:%x = %x\n", root->vendor, root->device, lnkcap); + return 0; +} +EXPORT_SYMBOL(drm_pcie_get_max_link_width); + #else int drm_pci_init(struct drm_driver *driver, struct pci_driver *pdriver) |