drm/amd: Fix detection of _PR3 on the PCIe root port

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@vger.kernel.org
Suggested-by: Jun Ma <Jun.Ma2@amd.com>
Tested-by: David Perry <David.Perry@amd.com>
Fixes: b10c1c5b3a4e ("drm/amdgpu: add check for ACPI power resources")
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 30c4f5cca02c9f6f6f4aaffc363158ca8145c43e..2b8356699f235dc2e18f991b70e18de56200e5c2 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -2093,7 +2093,7 @@ 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;
        }