On Wed, 12 Aug 2026, Andre Eikmeyer wrote:
> The MacBookPro15,1 uses Apple GMUX to control power to the discrete GPU,
> but it does not expose the ATPX or ACPI power-resource interfaces currently
> recognized by amdgpu. The driver therefore leaves runtime PM disabled even
> though vga_switcheroo can switch the GPU reliably.
>
> A dedicated GMUX runtime PM mode uses the existing vga_switcheroo PM domain
> to sequence GPU power. A runtime-suspended GMUX GPU can remain powered off
> across system sleep, following the smart-suspend handling already used by
> BOCO devices.
>
> This allows the discrete GPU to enter D3cold while the integrated GPU is
> primary and allows PRIME workloads and external displays to wake it on
> demand. The model enablement is limited to the tested MacBookPro15,1.
>
> This was tested on both the 2018 and 2019 MacBookPro15,1 revisions together
> with the apple-gmux and HDA changes in this series.
>
> Signed-off-by: Andre Eikmeyer <[email protected]>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 +
> drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 34 ++++++++++++++++++----
> drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 30 ++++++++++++-------
> drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h | 1 +
> 4 files changed, 49 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 7b09410..cc2e2e2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -1402,6 +1402,7 @@ int amdgpu_device_mode1_reset(struct amdgpu_device
> *adev);
> int amdgpu_device_link_reset(struct amdgpu_device *adev);
> bool amdgpu_device_supports_atpx(struct amdgpu_device *adev);
> bool amdgpu_device_supports_px(struct amdgpu_device *adev);
> +bool amdgpu_device_supports_gmux(struct amdgpu_device *adev);
> bool amdgpu_device_supports_boco(struct amdgpu_device *adev);
> bool amdgpu_device_supports_smart_shift(struct amdgpu_device *adev);
> int amdgpu_device_supports_baco(struct amdgpu_device *adev);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index bff3e06..bfa2b7a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -34,6 +34,7 @@
> #include <linux/slab.h>
> #include <linux/iommu.h>
> #include <linux/pci.h>
> +#include <linux/dmi.h>
> #include <linux/pci-p2pdma.h>
> #include <linux/apple-gmux.h>
> #include <linux/nospec.h>
> @@ -568,6 +569,22 @@ bool amdgpu_device_supports_px(struct amdgpu_device
> *adev)
> return false;
> }
>
> +static const struct dmi_system_id amdgpu_gmux_runpm_dmi_table[] = {
> + {
> + .matches = {
> + DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro15,1"),
> + },
> + },
> + { }
> +};
> +
> +bool amdgpu_device_supports_gmux(struct amdgpu_device *adev)
> +{
> + return dmi_check_system(amdgpu_gmux_runpm_dmi_table) &&
> + !dev_is_removable(&adev->pdev->dev) &&
> + apple_gmux_detect(NULL, NULL);
> +}
> +
> /**
> * amdgpu_device_supports_boco - Is the device a dGPU with ACPI power
> resources
> *
> @@ -631,6 +648,9 @@ void amdgpu_device_detect_runtime_pm_mode(struct
> amdgpu_device *adev)
> /* enable PX as runtime mode */
> adev->pm.rpm_mode = AMDGPU_RUNPM_PX;
> dev_info(adev->dev, "Using ATPX for runtime pm\n");
> + } else if (amdgpu_device_supports_gmux(adev)) {
> + adev->pm.rpm_mode = AMDGPU_RUNPM_GMUX;
> + dev_info(adev->dev, "Using Apple GMUX for runtime
> pm\n");
> } else if (amdgpu_device_supports_boco(adev)) {
> /* enable boco as runtime mode */
> adev->pm.rpm_mode = AMDGPU_RUNPM_BOCO;
> @@ -3711,7 +3731,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
> {
> struct pci_dev *pdev = adev->pdev;
> int r, i;
> - bool px = false;
> + bool gmux, px = false;
> u32 max_MBps;
> int tmp;
>
> @@ -4144,13 +4164,14 @@ fence_driver_init:
> vga_client_register(adev->pdev, amdgpu_device_vga_set_decode);
>
> px = amdgpu_device_supports_px(adev);
> + gmux = amdgpu_device_supports_gmux(adev);
>
> if (px || (!dev_is_removable(&adev->pdev->dev) &&
> - apple_gmux_detect(NULL, NULL)))
> + apple_gmux_detect(NULL, NULL)))
Please don't make unrelated space changes in a logic change.
> vga_switcheroo_register_client(adev->pdev,
> - &amdgpu_switcheroo_ops, px);
> + &amdgpu_switcheroo_ops, px ||
> gmux);
>
> - if (px)
> + if (px || gmux)
> vga_switcheroo_init_domain_pm_ops(adev->dev,
> &adev->vga_pm_domain);
>
> adev->pm_nb.notifier_call = amdgpu_device_pm_notifier;
> @@ -4278,7 +4299,7 @@ void amdgpu_device_fini_hw(struct amdgpu_device *adev)
> void amdgpu_device_fini_sw(struct amdgpu_device *adev)
> {
> int i, idx;
> - bool px;
> + bool gmux, px;
>
> amdgpu_device_ip_fini(adev);
> amdgpu_fence_driver_sw_fini(adev);
> @@ -4309,12 +4330,13 @@ void amdgpu_device_fini_sw(struct amdgpu_device *adev)
> adev->xcp_mgr = NULL;
>
> px = amdgpu_device_supports_px(adev);
> + gmux = amdgpu_device_supports_gmux(adev);
>
> if (px || (!dev_is_removable(&adev->pdev->dev) &&
> apple_gmux_detect(NULL, NULL)))
> vga_switcheroo_unregister_client(adev->pdev);
>
> - if (px)
> + if (px || gmux)
> vga_switcheroo_fini_domain_pm_ops(adev->dev);
>
> if ((adev->pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 1aed121..b8d4273 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -2485,11 +2485,12 @@ retry_init:
> DRM_ERROR("Creating debugfs files failed (%d).\n", ret);
>
> if (adev->pm.rpm_mode != AMDGPU_RUNPM_NONE) {
> - /* only need to skip on ATPX */
> + /* ATPX requires a full system-sleep transition. */
> if (amdgpu_device_supports_px(adev))
> dev_pm_set_driver_flags(ddev->dev,
> DPM_FLAG_NO_DIRECT_COMPLETE);
> - /* we want direct complete for BOCO */
> - if (amdgpu_device_supports_boco(adev))
> + /* BOCO and GMUX can remain runtime suspended across system
> sleep. */
> + if (amdgpu_device_supports_boco(adev) ||
> + adev->pm.rpm_mode == AMDGPU_RUNPM_GMUX)
> dev_pm_set_driver_flags(ddev->dev,
> DPM_FLAG_SMART_PREPARE |
> DPM_FLAG_SMART_SUSPEND |
> DPM_FLAG_MAY_SKIP_RESUME);
> @@ -2598,7 +2599,9 @@ static int amdgpu_pmops_prepare(struct device *dev)
> /* Return a positive number here so
> * DPM_FLAG_SMART_SUSPEND works properly
> */
> - if (amdgpu_device_supports_boco(adev) && pm_runtime_suspended(dev))
> + if ((amdgpu_device_supports_boco(adev) ||
> + adev->pm.rpm_mode == AMDGPU_RUNPM_GMUX) &&
> + pm_runtime_suspended(dev))
> return 1;
>
> /* if we will not support s3 or s2i for the device
> @@ -2860,7 +2863,8 @@ static int amdgpu_pmops_runtime_suspend(struct device
> *dev)
> }
>
> adev->in_runpm = true;
> - if (adev->pm.rpm_mode == AMDGPU_RUNPM_PX)
> + if (adev->pm.rpm_mode == AMDGPU_RUNPM_PX ||
> + adev->pm.rpm_mode == AMDGPU_RUNPM_GMUX)
> drm_dev->switch_power_state = DRM_SWITCH_POWER_CHANGING;
>
> /*
> @@ -2887,8 +2891,9 @@ static int amdgpu_pmops_runtime_suspend(struct device
> *dev)
> if (adev->pm.rpm_mode == AMDGPU_RUNPM_BOCO)
> adev->mp1_state = PP_MP1_STATE_NONE;
>
> - if (adev->pm.rpm_mode == AMDGPU_RUNPM_PX) {
> - /* Only need to handle PCI state in the driver for ATPX
> + if (adev->pm.rpm_mode == AMDGPU_RUNPM_PX ||
> + adev->pm.rpm_mode == AMDGPU_RUNPM_GMUX) {
> + /* Only need to handle PCI state in the driver for ATPX and
> GMUX.
> * PCI core handles it for _PR3.
> */
> amdgpu_device_cache_pci_state(pdev);
> @@ -2935,10 +2940,11 @@ static int amdgpu_pmops_runtime_resume(struct device
> *dev)
> if (!pci_device_is_present(adev->pdev))
> adev->no_hw_access = true;
>
> - if (adev->pm.rpm_mode == AMDGPU_RUNPM_PX) {
> + if (adev->pm.rpm_mode == AMDGPU_RUNPM_PX ||
> + adev->pm.rpm_mode == AMDGPU_RUNPM_GMUX) {
> drm_dev->switch_power_state = DRM_SWITCH_POWER_CHANGING;
>
> - /* Only need to handle PCI state in the driver for ATPX
> + /* Only need to handle PCI state in the driver for ATPX and
> GMUX.
> * PCI core handles it for _PR3.
> */
> pci_set_power_state(pdev, PCI_D0);
> @@ -2958,12 +2964,14 @@ static int amdgpu_pmops_runtime_resume(struct device
> *dev)
> }
> ret = amdgpu_device_resume(drm_dev, false);
> if (ret) {
> - if (adev->pm.rpm_mode == AMDGPU_RUNPM_PX)
> + if (adev->pm.rpm_mode == AMDGPU_RUNPM_PX ||
> + adev->pm.rpm_mode == AMDGPU_RUNPM_GMUX)
> pci_disable_device(pdev);
> return ret;
> }
>
> - if (adev->pm.rpm_mode == AMDGPU_RUNPM_PX)
> + if (adev->pm.rpm_mode == AMDGPU_RUNPM_PX ||
> + adev->pm.rpm_mode == AMDGPU_RUNPM_GMUX)
Maybe helper to check these? (But I'm not the maintainer for this code so
I don't know what they want.)
> drm_dev->switch_power_state = DRM_SWITCH_POWER_ON;
>
> amdgpu_restore_umd_profile_pstate_after_runpm(adev);
> diff --git a/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
> b/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
> index 8d1b097..df24b01 100644
> --- a/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
> +++ b/drivers/gpu/drm/amd/pm/inc/amdgpu_dpm.h
> @@ -48,6 +48,7 @@ enum amdgpu_int_thermal_type {
> enum amdgpu_runpm_mode {
> AMDGPU_RUNPM_NONE,
> AMDGPU_RUNPM_PX,
> + AMDGPU_RUNPM_GMUX,
> AMDGPU_RUNPM_BOCO,
> AMDGPU_RUNPM_BACO,
> AMDGPU_RUNPM_BAMACO,
>
--
i.
