Re: [PATCH v3 2/4] drm/msm/dpu: Enable widebus for DSI INTF

[Dmitry Baryshkov]

On Wed, 2 Aug 2023 at 21:09, Jessica Zhang <quic_jesszhan@xxxxxxxxxxx> wrote:
>
> DPU supports a data-bus widen mode for DSI INTF.
>
> Enable this mode for all supported chipsets if widebus is enabled for DSI.
>
> Signed-off-by: Jessica Zhang <quic_jesszhan@xxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c          | 11 ++++++++---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c |  4 +++-
>  drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c          |  3 +++
>  drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h          |  1 +
>  drivers/gpu/drm/msm/msm_drv.h                        |  6 +++++-
>  5 files changed, 20 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index 3dcd37c48aac..de08aad39e15 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -1196,15 +1196,20 @@ static void dpu_encoder_virt_atomic_enable(struct drm_encoder *drm_enc,
>         struct drm_display_mode *cur_mode = NULL;
>         struct msm_drm_private *priv = drm_enc->dev->dev_private;
>         struct msm_display_info *disp_info;
> +       int index;
>
>         dpu_enc = to_dpu_encoder_virt(drm_enc);
>         disp_info = &dpu_enc->disp_info;
>
> +       disp_info = &dpu_enc->disp_info;
> +       index = disp_info->h_tile_instance[0];
> +
>         dpu_enc->dsc = dpu_encoder_get_dsc_config(drm_enc);
>
> -       if (disp_info->intf_type == INTF_DP)
> -               dpu_enc->wide_bus_en = msm_dp_wide_bus_available(
> -                               priv->dp[disp_info->h_tile_instance[0]]);
> +       if (disp_info->intf_type == INTF_DSI)
> +               dpu_enc->wide_bus_en = msm_dsi_is_widebus_enabled(priv->dsi[index]);
> +       else if (disp_info->intf_type == INTF_DP)
> +               dpu_enc->wide_bus_en = msm_dp_wide_bus_available(priv->dp[index]);

If you change the order, you won't have to touch DP lines.

>
>         mutex_lock(&dpu_enc->enc_lock);
>         cur_mode = &dpu_enc->base.crtc->state->adjusted_mode;
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> index df88358e7037..dace6168be2d 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_cmd.c
> @@ -69,8 +69,10 @@ static void _dpu_encoder_phys_cmd_update_intf_cfg(
>                                 phys_enc->hw_intf,
>                                 phys_enc->hw_pp->idx);
>
> -       if (intf_cfg.dsc != 0)
> +       if (intf_cfg.dsc != 0) {
>                 cmd_mode_cfg.data_compress = true;
> +               cmd_mode_cfg.wide_bus_en = dpu_encoder_is_widebus_enabled(phys_enc->parent);
> +       }

This embeds the knowledge that a wide bus can only be enabled when DSC
is in use. Please move the wide_bus_en assignment out of conditional
code.

>
>         if (phys_enc->hw_intf->ops.program_intf_cmd_cfg)
>                 phys_enc->hw_intf->ops.program_intf_cmd_cfg(phys_enc->hw_intf, &cmd_mode_cfg);
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
> index 8ec6505d9e78..dc6f3febb574 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
> @@ -521,6 +521,9 @@ static void dpu_hw_intf_program_intf_cmd_cfg(struct dpu_hw_intf *ctx,

This function is only enabled for DPU >= 7.0, while IIRC wide bus can
be enabled even for some of the earlier chipsets.

>         if (cmd_mode_cfg->data_compress)
>                 intf_cfg2 |= INTF_CFG2_DCE_DATA_COMPRESS;
>
> +       if (cmd_mode_cfg->wide_bus_en)
> +               intf_cfg2 |= INTF_CFG2_DATABUS_WIDEN;
> +
>         DPU_REG_WRITE(&ctx->hw, INTF_CONFIG2, intf_cfg2);
>  }
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
> index 77f80531782b..c539025c418b 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
> @@ -50,6 +50,7 @@ struct dpu_hw_intf_status {
>
>  struct dpu_hw_intf_cmd_mode_cfg {
>         u8 data_compress;       /* enable data compress between dpu and dsi */
> +       u8 wide_bus_en;         /* enable databus widen mode */
>  };
>
>  /**
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index 9d9d5e009163..e4f706b16aad 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -344,6 +344,7 @@ void msm_dsi_snapshot(struct msm_disp_state *disp_state, struct msm_dsi *msm_dsi
>  bool msm_dsi_is_cmd_mode(struct msm_dsi *msm_dsi);
>  bool msm_dsi_is_bonded_dsi(struct msm_dsi *msm_dsi);
>  bool msm_dsi_is_master_dsi(struct msm_dsi *msm_dsi);
> +bool msm_dsi_is_widebus_enabled(struct msm_dsi *msm_dsi);
>  struct drm_dsc_config *msm_dsi_get_dsc_config(struct msm_dsi *msm_dsi);
>  #else
>  static inline void __init msm_dsi_register(void)
> @@ -373,7 +374,10 @@ static inline bool msm_dsi_is_master_dsi(struct msm_dsi *msm_dsi)
>  {
>         return false;
>  }
> -
> +static inline bool msm_dsi_is_widebus_enabled(struct msm_dsi *msm_dsi)
> +{
> +       return false;
> +}

Empty line, please.

>  static inline struct drm_dsc_config *msm_dsi_get_dsc_config(struct msm_dsi *msm_dsi)
>  {
>         return NULL;
>
> --
> 2.41.0
>


-- 
With best wishes
Dmitry