[PATCH] drm/amd: Propagate failures in dc_set_power_state()

[Alex Deucher]

On Fri, Sep 22, 2023 at 4:51 PM Mario Limonciello
<mario.limonciello at amd.com> wrote:
>
> During the suspend process dc_set_power_state() will use kzalloc
> to allocate memory, but this potentially fails with memory pressure.
> If it fails, the suspend should be aborted.
>
> Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2362
> Signed-off-by: Mario Limonciello <mario.limonciello at amd.com>

Acked-by: Alex Deucher <alexander.deucher at amd.com>

> ---
> Cc: Harry.Wentland at amd.com
>  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 13 ++++++++-----
>  drivers/gpu/drm/amd/display/dc/core/dc.c          |  8 +++++---
>  drivers/gpu/drm/amd/display/dc/dc.h               |  2 +-
>  3 files changed, 14 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index 373884ca38b9..2acb555343ae 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -2670,9 +2670,7 @@ static int dm_suspend(void *handle)
>
>         hpd_rx_irq_work_suspend(dm);
>
> -       dc_set_power_state(dm->dc, DC_ACPI_CM_POWER_STATE_D3);
> -
> -       return 0;
> +       return dc_set_power_state(dm->dc, DC_ACPI_CM_POWER_STATE_D3);
>  }
>
>  struct amdgpu_dm_connector *
> @@ -2865,7 +2863,10 @@ static int dm_resume(void *handle)
>                 if (r)
>                         DRM_ERROR("DMUB interface failed to initialize: status=%d\n", r);
>
> -               dc_set_power_state(dm->dc, DC_ACPI_CM_POWER_STATE_D0);
> +               r = dc_set_power_state(dm->dc, DC_ACPI_CM_POWER_STATE_D0);
> +               if (r)
> +                       return r;
> +
>                 dc_resume(dm->dc);
>
>                 amdgpu_dm_irq_resume_early(adev);
> @@ -2914,7 +2915,9 @@ static int dm_resume(void *handle)
>         }
>
>         /* power on hardware */
> -       dc_set_power_state(dm->dc, DC_ACPI_CM_POWER_STATE_D0);
> +       r = dc_set_power_state(dm->dc, DC_ACPI_CM_POWER_STATE_D0);
> +       if (r)
> +               return r;
>
>         /* program HPD filter */
>         dc_resume(dm->dc);
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
> index 293489c41086..a1593d550526 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
> @@ -4711,7 +4711,7 @@ void dc_power_down_on_boot(struct dc *dc)
>                 dc->hwss.power_down_on_boot(dc);
>  }
>
> -void dc_set_power_state(
> +int dc_set_power_state(
>         struct dc *dc,
>         enum dc_acpi_cm_power_state power_state)
>  {
> @@ -4719,7 +4719,7 @@ void dc_set_power_state(
>         struct display_mode_lib *dml;
>
>         if (!dc->current_state)
> -               return;
> +               return 0;
>
>         switch (power_state) {
>         case DC_ACPI_CM_POWER_STATE_D0:
> @@ -4746,7 +4746,7 @@ void dc_set_power_state(
>
>                 ASSERT(dml);
>                 if (!dml)
> -                       return;
> +                       return -ENOMEM;
>
>                 /* Preserve refcount */
>                 refcount = dc->current_state->refcount;
> @@ -4764,6 +4764,8 @@ void dc_set_power_state(
>
>                 break;
>         }
> +
> +       return 0;
>  }
>
>  void dc_resume(struct dc *dc)
> diff --git a/drivers/gpu/drm/amd/display/dc/dc.h b/drivers/gpu/drm/amd/display/dc/dc.h
> index faf897ac75d8..82013ebcba91 100644
> --- a/drivers/gpu/drm/amd/display/dc/dc.h
> +++ b/drivers/gpu/drm/amd/display/dc/dc.h
> @@ -2329,7 +2329,7 @@ void dc_notify_vsync_int_state(struct dc *dc, struct dc_stream_state *stream, bo
>
>  /* Power Interfaces */
>
> -void dc_set_power_state(
> +int dc_set_power_state(
>                 struct dc *dc,
>                 enum dc_acpi_cm_power_state power_state);
>  void dc_resume(struct dc *dc);
> --
> 2.34.1
>