drm/amdgpu: fix check for port PM availability

Lekensteyn · alexdeucher · commit 7ac33e47d576 · 2016-11-29T09:23:39.000-05:00
The ATPX method does not always exist on the dGPU, it may be located at the iGPU. The parent device of the iGPU is the root port for which bridge_d3 is false. This accidentally enables the legacy PM method which conflicts with port PM and prevented the dGPU from powering on. Fixes: 1db4496 ("drm/amdgpu: fix power state when port pm is unavailable") Reported-and-tested-by: Mike Lothian <mike@fireburn.co.uk> Signed-off-by: Peter Wu <peter@lekensteyn.nl> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Cc: <stable@vger.kernel.org> # 4.8+
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c
@@ -485,7 +485,6 @@ static int amdgpu_atpx_power_state(enum vga_switcheroo_client_id id,
  */
 static bool amdgpu_atpx_pci_probe_handle(struct pci_dev *pdev)
 {
-	struct pci_dev *parent_pdev = pci_upstream_bridge(pdev);
 	acpi_handle dhandle, atpx_handle;
 	acpi_status status;
 
@@ -500,7 +499,6 @@ static bool amdgpu_atpx_pci_probe_handle(struct pci_dev *pdev)
 	}
 	amdgpu_atpx_priv.dhandle = dhandle;
 	amdgpu_atpx_priv.atpx.handle = atpx_handle;
-	amdgpu_atpx_priv.bridge_pm_usable = parent_pdev && parent_pdev->bridge_d3;
 	return true;
 }
 
@@ -562,24 +560,33 @@ static bool amdgpu_atpx_detect(void)
 	struct pci_dev *pdev = NULL;
 	bool has_atpx = false;
 	int vga_count = 0;
+	bool d3_supported = false;
+	struct pci_dev *parent_pdev;
 
 	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
 		vga_count++;
 
 		has_atpx |= (amdgpu_atpx_pci_probe_handle(pdev) == true);
+
+		parent_pdev = pci_upstream_bridge(pdev);
+		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
 	}
 
 	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) != NULL) {
 		vga_count++;
 
 		has_atpx |= (amdgpu_atpx_pci_probe_handle(pdev) == true);
+
+		parent_pdev = pci_upstream_bridge(pdev);
+		d3_supported |= parent_pdev && parent_pdev->bridge_d3;
 	}
 
 	if (has_atpx && vga_count == 2) {
 		acpi_get_name(amdgpu_atpx_priv.atpx.handle, ACPI_FULL_PATHNAME, &buffer);
 		printk(KERN_INFO "vga_switcheroo: detected switching method %s handle\n",
 		       acpi_method_name);
 		amdgpu_atpx_priv.atpx_detected = true;
+		amdgpu_atpx_priv.bridge_pm_usable = d3_supported;
 		amdgpu_atpx_init();
 		return true;
 	}
