Use PCI Express Capability access functions to simplify this code a bit.
For non-PCIe devices or pre-PCIe 3.0 devices that don't implement the Link
Capabilities 2 register, pcie_capability_read_dword() reads a zero.
Since we're only testing whether the bits we care about are set, there's no
need to mask out the other bits we *don't* care about.
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/gpu/drm/drm_pci.c | 21 +++++----------------
1 files changed, 5 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/drm_pci.c b/drivers/gpu/drm/drm_pci.c
index 50e26f2..86102a0 100644
--- a/drivers/gpu/drm/drm_pci.c
+++ b/drivers/gpu/drm/drm_pci.c
@@ -469,41 +469,30 @@ 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 = 0, lnkcap2 = 0;
+ 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;
+ pcie_capability_read_dword(root, PCI_EXP_LNKCAP, &lnkcap);
+ pcie_capability_read_dword(root, PCI_EXP_LNKCAP2, &lnkcap2);
- if (lnkcap2) { /* PCIE GEN 3.0 */
+ if (lnkcap2) { /* PCIe r3.0-compliant */
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 {
+ } else { /* pre-r3.0 */
if (lnkcap & PCI_EXP_LNKCAP_SLS_2_5GB)
*mask |= DRM_PCIE_SPEED_25;
if (lnkcap & PCI_EXP_LNKCAP_SLS_5_0GB)
--
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