[PATCH 1/3] drm/amd: Fix detection of _PR3 on the PCIe root port

[Mario Limonciello]

On some systems with Navi3x dGPU will attempt to use BACO for runtime
PM but fails to resume properly.  This is because on these systems
the root port goes into D3cold which is incompatible with BACO.

This happens because in this case dGPU is connected to a bridge between
root port which causes BOCO detection logic to fail.  Fix the intent of
the logic by looking at root port, not the immediate upstream bridge for
_PR3.

Cc: stable at vger.kernel.org
Suggested-by: Jun Ma <Jun.Ma2 at amd.com>
Tested-by: David Perry <David.Perry at amd.com>
Fixes: b10c1c5b3a4e ("drm/amdgpu: add check for ACPI power resources")
Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index e4627d92e1d0..bad2b5577e96 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -2238,7 +2238,7 @@ static int amdgpu_device_ip_early_init(struct amdgpu_device *adev)
 		adev->flags |= AMD_IS_PX;
 
 	if (!(adev->flags & AMD_IS_APU)) {
-		parent = pci_upstream_bridge(adev->pdev);
+		parent = pcie_find_root_port(adev->pdev);
 		adev->has_pr3 = parent ? pci_pr3_present(parent) : false;
 	}
 
-- 
2.34.1