Re: [RFC PATCH 9/9] drm/amdgpu: register a vga_switcheroo client for all GPUs that are not thunderbolt attached

[Alex Deucher]

On Fri, Feb 10, 2023 at 3:04 AM Orlando Chamberlain
<orlandoch.dev@xxxxxxxxx> wrote:
>
> From: Kerem Karabay <kekrby@xxxxxxxxx>
>
> Commit 3840c5bcc245 ("drm/amdgpu: disentangle runtime pm and
> vga_switcheroo") made amdgpu only register a vga_switcheroo client for
> GPU's with PX, however AMD GPUs in dual gpu Apple Macbooks do need to
> register, but don't have PX. Instead of AMD's PX, they use apple-gmux.

Is there a way to detect apple-gmux instead?  Otherwise, we register
vga_switcheroo on any system with multiple GPUs which is not what we
want.

Alex

>
> Revert to the old logic of registering for all non-thunderbolt gpus,
> like radeon and nouveau.
>
> Fixes: 3840c5bcc245 ("drm/amdgpu: disentangle runtime pm and vga_switcheroo")
> Signed-off-by: Kerem Karabay <kekrby@xxxxxxxxx>
> [Orlando Chamberlain <orlandoch.dev@xxxxxxxxx>: add commit description]
> Signed-off-by: Orlando Chamberlain <orlandoch.dev@xxxxxxxxx>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 2f28a8c02f64..0bb553a61552 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -3919,12 +3919,13 @@ int amdgpu_device_init(struct amdgpu_device *adev,
>         if ((adev->pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
>                 vga_client_register(adev->pdev, amdgpu_device_vga_set_decode);
>
> -       if (amdgpu_device_supports_px(ddev)) {
> -               px = true;
> -               vga_switcheroo_register_client(adev->pdev,
> -                                              &amdgpu_switcheroo_ops, px);
> +       px = amdgpu_device_supports_px(ddev);
> +
> +       if (!pci_is_thunderbolt_attached(adev->pdev))
> +               vga_switcheroo_register_client(adev->pdev, &amdgpu_switcheroo_ops, px);
> +
> +       if (px)
>                 vga_switcheroo_init_domain_pm_ops(adev->dev, &adev->vga_pm_domain);
> -       }
>
>         if (adev->gmc.xgmi.pending_reset)
>                 queue_delayed_work(system_wq, &mgpu_info.delayed_reset_work,
> @@ -4048,10 +4049,13 @@ void amdgpu_device_fini_sw(struct amdgpu_device *adev)
>
>         kfree(adev->bios);
>         adev->bios = NULL;
> -       if (amdgpu_device_supports_px(adev_to_drm(adev))) {
> +
> +       if (!pci_is_thunderbolt_attached(adev->pdev))
>                 vga_switcheroo_unregister_client(adev->pdev);
> +
> +       if (amdgpu_device_supports_px(adev_to_drm(adev)))
>                 vga_switcheroo_fini_domain_pm_ops(adev->dev);
> -       }
> +
>         if ((adev->pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
>                 vga_client_unregister(adev->pdev);
>
> --
> 2.39.1
>