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) diff --git a/include/drm/drmP.h b/include/drm/drmP.h index 30d4a5a495e2..bd5d2c536ddc 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1098,6 +1098,7 @@ static inline int drm_pci_set_busid(struct drm_device *dev, #define DRM_PCIE_SPEED_80 4 extern int drm_pcie_get_speed_cap_mask(struct drm_device *dev, u32 *speed_mask); +extern int drm_pcie_get_max_link_width(struct drm_device *dev, u32 *mlw); /* platform section */ extern int drm_platform_init(struct drm_driver *driver, struct platform_device *platform_device);