Prevent runtime suspend of non-PX GPUs.  Runtime suspend is
not what we want in those cases.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
        if (radeon_runtime_pm == 0)
                return -EINVAL;
 
+       if (radeon_runtime_pm == -1 && !radeon_is_px())
+               return -EINVAL;
+
        drm_dev->switch_power_state = DRM_SWITCH_POWER_CHANGING;
        drm_kms_helper_poll_disable(drm_dev);
        vga_switcheroo_set_dynamic_switch(pdev, VGA_SWITCHEROO_OFF);
        if (radeon_runtime_pm == 0)
                return -EINVAL;
 
+       if (radeon_runtime_pm == -1 && !radeon_is_px())
+               return -EINVAL;
+
        drm_dev->switch_power_state = DRM_SWITCH_POWER_CHANGING;
 
        pci_set_power_state(pdev, PCI_D0);