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path: root/drivers/gpu/drm/drm_pci.c
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Diffstat (limited to 'drivers/gpu/drm/drm_pci.c')
-rw-r--r--drivers/gpu/drm/drm_pci.c20
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)