[PATCH v5 6/7] drm/amd/display: Destroy DC context while keeping DML and DML2

[Alex Deucher]

On Sat, Oct 7, 2023 at 3:47 AM Mario Limonciello
<mario.limonciello at amd.com> wrote:
>
> If there is memory pressure at suspend time then dynamically
> allocating a large structure as part of DC suspend code will
> fail.
>
> Instead re-use the same structures and clear all members except
> those that should be maintained.
>
> 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>

> ---
> v4->v5:
>  * Rebase for DML2
> ---
>  drivers/gpu/drm/amd/display/dc/core/dc.c      | 37 -------------------
>  .../gpu/drm/amd/display/dc/core/dc_resource.c | 12 ++++++
>  2 files changed, 12 insertions(+), 37 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
> index 2436a293931b..55e7b5a8ec8e 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
> @@ -4704,12 +4704,6 @@ bool dc_set_power_state(
>         struct dc *dc,
>         enum dc_acpi_cm_power_state power_state)
>  {
> -       struct kref refcount;
> -       struct display_mode_lib *dml;
> -#ifdef CONFIG_DRM_AMD_DC_FP
> -       struct dml2_context *dml2 = NULL;
> -#endif
> -
>         if (!dc->current_state)
>                 return true;
>
> @@ -4728,40 +4722,9 @@ bool dc_set_power_state(
>
>                 break;
>         default:
> -#ifdef CONFIG_DRM_AMD_DC_FP
> -               if (dc->debug.using_dml2)
> -                       dml2 = dc->current_state->bw_ctx.dml2;
> -#endif
>                 ASSERT(dc->current_state->stream_count == 0);
> -               /* Zero out the current context so that on resume we start with
> -                * clean state, and dc hw programming optimizations will not
> -                * cause any trouble.
> -                */
> -               dml = kzalloc(sizeof(struct display_mode_lib),
> -                               GFP_KERNEL);
> -
> -               ASSERT(dml);
> -               if (!dml)
> -                       return false;
> -
> -               /* Preserve refcount */
> -               refcount = dc->current_state->refcount;
> -               /* Preserve display mode lib */
> -               memcpy(dml, &dc->current_state->bw_ctx.dml, sizeof(struct display_mode_lib));
>
>                 dc_resource_state_destruct(dc->current_state);
> -               memset(dc->current_state, 0,
> -                               sizeof(*dc->current_state));
> -
> -               dc->current_state->refcount = refcount;
> -               dc->current_state->bw_ctx.dml = *dml;
> -
> -               kfree(dml);
> -
> -#ifdef CONFIG_DRM_AMD_DC_FP
> -               if (dc->debug.using_dml2)
> -                       dc->current_state->bw_ctx.dml2 = dml2;
> -#endif
>
>                 break;
>         }
> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
> index c1e2f0e10ab2..e2c7acdff301 100644
> --- a/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
> +++ b/drivers/gpu/drm/amd/display/dc/core/dc_resource.c
> @@ -4357,6 +4357,18 @@ void dc_resource_state_destruct(struct dc_state *context)
>                 context->streams[i] = NULL;
>         }
>         context->stream_count = 0;
> +       context->stream_mask = 0;
> +       memset(&context->res_ctx, 0, sizeof(context->res_ctx));
> +       memset(&context->pp_display_cfg, 0, sizeof(context->pp_display_cfg));
> +       memset(&context->dcn_bw_vars, 0, sizeof(context->dcn_bw_vars));
> +       context->clk_mgr = NULL;
> +       memset(&context->bw_ctx.bw, 0, sizeof(context->bw_ctx.bw));
> +       memset(context->block_sequence, 0, sizeof(context->block_sequence));
> +       context->block_sequence_steps = 0;
> +       memset(context->dc_dmub_cmd, 0, sizeof(context->dc_dmub_cmd));
> +       context->dmub_cmd_count = 0;
> +       memset(&context->perf_params, 0, sizeof(context->perf_params));
> +       memset(&context->scratch, 0, sizeof(context->scratch));
>  }
>
>  void dc_resource_state_copy_construct(
> --
> 2.34.1
>