Re: [PATCH 12/13] drm/amdgpu: Skip AC/DC notification while the GPU is runtime suspended

[Alex Deucher]

On Sun, Oct 25, 2026 at 12:11 AM Atharva Tiwari
<atharvatiwarilinuxdev@xxxxxxxxx> wrote:
>
> From: Andre Eikmeyer <dev@deq.rocks>
>
> Plugging or unplugging the charger raises an ACPI AC event. The handler
> sent the new power source to the SMU without a runtime PM reference, so
> with GMUX keeping the GPU off every SMU message spun on skipped register
> reads for seconds. A runtime resume racing with that left the SMU
> firmware unable to start on MacBookPro15,1 and the GPU in runtime PM
> error state. Record the power source only and let the resume apply it.
>
> Signed-off-by: Atharva Tiwari <atharvatiwarilinuxdev@xxxxxxxxx>
> Signed-off-by: Andre Eikmeyer <dev@deq.rocks>
> ---
>  drivers/gpu/drm/amd/pm/amdgpu_dpm.c | 19 +++++++++++++------
>  1 file changed, 13 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> index 808be6c42..b64f0b681 100644
> --- a/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> +++ b/drivers/gpu/drm/amd/pm/amdgpu_dpm.c
> @@ -30,6 +30,7 @@
>  #include "amd_pcie.h"
>  #include "amdgpu_display.h"
>  #include "hwmgr.h"
> +#include <linux/pm_runtime.h>
>  #include <linux/power_supply.h>
>  #include "amdgpu_smu.h"
>
> @@ -498,20 +499,26 @@ int amdgpu_dpm_smu_i2c_bus_access(struct amdgpu_device *adev,
>
>  void amdgpu_pm_acpi_event_handler(struct amdgpu_device *adev)
>  {
> +       int active = 0;
> +
>         if (adev->pm.dpm_enabled) {
>                 mutex_lock(&adev->pm.mutex);
> +               active = adev->pm.rpm_mode == AMDGPU_RUNPM_GMUX ?
> +                               pm_runtime_get_if_active(adev->dev) : 1;

There's no reason this needs to be GMUX only.  You can drop the
AMDGPU_RUNPM_GMUX check here.

Alex

> +
>                 if (power_supply_is_system_supplied() > 0)
>                         adev->pm.ac_power = true;
>                 else
>                         adev->pm.ac_power = false;
>
> -               if (adev->powerplay.pp_funcs &&
> -                   adev->powerplay.pp_funcs->notify_ac_dc)
> -                       amdgpu_dpm_notify_ac_dc(adev);
> -
> -               if (is_support_sw_smu(adev))
> -                       smu_set_ac_dc(adev->powerplay.pp_handle, true);
> +               if (active) {
> +                       if (adev->powerplay.pp_funcs &&
> +                           adev->powerplay.pp_funcs->notify_ac_dc)
> +                               amdgpu_dpm_notify_ac_dc(adev);
>
> +                       if (is_support_sw_smu(adev))
> +                               smu_set_ac_dc(adev->powerplay.pp_handle, true);
> +               }
>                 mutex_unlock(&adev->pm.mutex);
>         }
>  }
> --
> 2.55.0
>