[PATCHv2] drm/amdgpu: register a vga_switcheroo client for MacBooks with apple-gmux

[Alex Deucher]

On Thu, Feb 16, 2023 at 8:45 AM Orlando Chamberlain
<orlandoch.dev at gmail.com> wrote:
>
> 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.
>
> Use apple_gmux_detect() to identify these gpus, and
> pci_is_thunderbolt_attached() to ensure eGPUs connected to Dual GPU
> Macbooks don't register with vga_switcheroo.
>
> Fixes: 3840c5bcc245 ("drm/amdgpu: disentangle runtime pm and vga_switcheroo")
> Link: https://lore.kernel.org/amd-gfx/20230210044826.9834-10-orlandoch.dev@gmail.com/
> Signed-off-by: Orlando Chamberlain <orlandoch.dev at gmail.com>

This needs ifdefs around the apple_gmux stuff so that it will build
without the gmux support.

Alex

> ---
> v1->v2: Use apple_gmux_detect()
>  drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 21 ++++++++++++++++-----
>  1 file changed, 16 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 2f28a8c02f64..ef8b996f0622 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -35,6 +35,7 @@
>  #include <linux/devcoredump.h>
>  #include <generated/utsrelease.h>
>  #include <linux/pci-p2pdma.h>
> +#include <linux/apple-gmux.h>
>
>  #include <drm/drm_aperture.h>
>  #include <drm/drm_atomic_helper.h>
> @@ -3919,12 +3920,15 @@ 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;
> +       px = amdgpu_device_supports_px(ddev);
> +
> +       if (px || (!pci_is_thunderbolt_attached(adev->pdev) &&
> +                               apple_gmux_detect(NULL, NULL)))
>                 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,
> @@ -4029,6 +4033,7 @@ void amdgpu_device_fini_hw(struct amdgpu_device *adev)
>  void amdgpu_device_fini_sw(struct amdgpu_device *adev)
>  {
>         int idx;
> +       bool px;
>
>         amdgpu_fence_driver_sw_fini(adev);
>         amdgpu_device_ip_fini(adev);
> @@ -4048,10 +4053,16 @@ void amdgpu_device_fini_sw(struct amdgpu_device *adev)
>
>         kfree(adev->bios);
>         adev->bios = NULL;
> -       if (amdgpu_device_supports_px(adev_to_drm(adev))) {
> +
> +       px = amdgpu_device_supports_px(adev_to_drm(adev));
> +
> +       if (px || (!pci_is_thunderbolt_attached(adev->pdev) &&
> +                               apple_gmux_detect(NULL, NULL)))
>                 vga_switcheroo_unregister_client(adev->pdev);
> +
> +       if (px)
>                 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
>