diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index b7751dde2894..520fd59036d5 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -1338,6 +1338,31 @@ static bool amdgpu_device_aspm_support_quirk(struct amdgpu_device *adev) #endif } +/* + * Some dGPUs expose their display endpoint below an internal PCIe switch. + * Use the switch upstream port to query the host-facing link. + */ +static struct pci_dev *amdgpu_device_get_aspm_pdev(struct amdgpu_device *adev) +{ + struct pci_dev *swds, *swus; + + swds = pci_upstream_bridge(adev->pdev); + if (!swds || + (swds->vendor != PCI_VENDOR_ID_ATI && + swds->vendor != PCI_VENDOR_ID_AMD) || + pci_pcie_type(swds) != PCI_EXP_TYPE_DOWNSTREAM) + return adev->pdev; + + swus = pci_upstream_bridge(swds); + if (!swus || + (swus->vendor != PCI_VENDOR_ID_ATI && + swus->vendor != PCI_VENDOR_ID_AMD) || + pci_pcie_type(swus) != PCI_EXP_TYPE_UPSTREAM) + return adev->pdev; + + return swus; +} + /** * amdgpu_device_should_use_aspm - check if the device should program ASPM * @@ -1350,6 +1375,9 @@ static bool amdgpu_device_aspm_support_quirk(struct amdgpu_device *adev) */ bool amdgpu_device_should_use_aspm(struct amdgpu_device *adev) { + struct pci_dev *aspm_pdev, *parent; + bool enabled; + switch (amdgpu_aspm) { case -1: break; @@ -1364,7 +1392,27 @@ bool amdgpu_device_should_use_aspm(struct amdgpu_device *adev) return false; if (amdgpu_device_aspm_support_quirk(adev)) return false; - return pcie_aspm_enabled(adev->pdev); + + /* + * pcie_aspm_enabled() checks the link between its argument and + * the immediate upstream bridge. Use SWUS for dGPUs with an + * internal switch so that this is the host-facing link. + */ + aspm_pdev = amdgpu_device_get_aspm_pdev(adev); + parent = pci_upstream_bridge(aspm_pdev); + if (!parent) { + dev_dbg(adev->dev, "ASPM: no upstream PCIe link for %s\n", + pci_name(aspm_pdev)); + return false; + } + + enabled = pcie_aspm_enabled(aspm_pdev); + /* Report the exact link used for the automatic ASPM decision. */ + dev_dbg(adev->dev, "ASPM: link %s <-> %s is %s\n", + pci_name(parent), pci_name(aspm_pdev), + enabled ? "enabled" : "disabled"); + + return enabled; } /* if we get transitioned to only one device, take VGA back */