Re: [PATCH] drm/msm/dpu: fix the programming of INTF_CFG2_DATA_HCTL_EN

[Dmitry Baryshkov]

On Thu, 1 Feb 2024 at 02:48, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:
>
> Currently INTF_CFG2_DATA_HCTL_EN is coupled with the enablement
> of widebus but this is incorrect because we should be enabling
> this bit independent of widebus except for cases where compression
> is enabled in one pixel per clock mode.
>
> Fix this by making the condition checks more explicit and enabling
> INTF_CFG2_DATA_HCTL_EN for all other cases when supported by DPU.
>
> Fixes: 3309a7563971 ("drm/msm/dpu: revise timing engine programming to support widebus feature")
> Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>

Thank you!

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>

For the reference: although it is marked as a fix, I'd prefer if this
patch undergoes a full cycle through msm-next rather than
fast-tracking through msm-fixes. This would allow us to catch possible
issues. WDYT?

> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c       |  7 +++++++
>  drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h       |  7 +++++++
>  .../gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c  |  1 +
>  drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c       | 15 +++++++++------
>  drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h       |  1 +
>  5 files changed, 25 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index 83380bc92a00..467f874979d5 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -230,6 +230,13 @@ bool dpu_encoder_is_widebus_enabled(const struct drm_encoder *drm_enc)
>         return dpu_enc->wide_bus_en;
>  }
>
> +bool dpu_encoder_is_dsc_enabled(const struct drm_encoder *drm_enc)
> +{
> +       const struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(drm_enc);
> +
> +       return dpu_enc->dsc ? true : false;
> +}
> +
>  int dpu_encoder_get_crc_values_cnt(const struct drm_encoder *drm_enc)
>  {
>         struct dpu_encoder_virt *dpu_enc;
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> index 4c05fd5e9ed1..fe6b1d312a74 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
> @@ -158,6 +158,13 @@ int dpu_encoder_get_vsync_count(struct drm_encoder *drm_enc);
>
>  bool dpu_encoder_is_widebus_enabled(const struct drm_encoder *drm_enc);
>
> +/**
> + * dpu_encoder_is_dsc_enabled - indicate whether dsc is enabled
> + *                             for the encoder.
> + * @drm_enc:    Pointer to previously created drm encoder structure
> + */
> +bool dpu_encoder_is_dsc_enabled(const struct drm_encoder *drm_enc);
> +
>  /**
>   * dpu_encoder_get_crc_values_cnt - get number of physical encoders contained
>   *     in virtual encoder that can collect CRC values
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> index d0f56c5c4cce..f562beb6f797 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> @@ -102,6 +102,7 @@ static void drm_mode_to_intf_timing_params(
>         }
>
>         timing->wide_bus_en = dpu_encoder_is_widebus_enabled(phys_enc->parent);
> +       timing->compression_en = dpu_encoder_is_dsc_enabled(phys_enc->parent);
>
>         /*
>          * for DP, divide the horizonal parameters by 2 when
> 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 6bba531d6dc4..965692ef7892 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
> @@ -163,13 +163,8 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *ctx,
>         hsync_ctl = (hsync_period << 16) | p->hsync_pulse_width;
>         display_hctl = (hsync_end_x << 16) | hsync_start_x;
>
> -       /*
> -        * DATA_HCTL_EN controls data timing which can be different from
> -        * video timing. It is recommended to enable it for all cases, except
> -        * if compression is enabled in 1 pixel per clock mode
> -        */
>         if (p->wide_bus_en)
> -               intf_cfg2 |= INTF_CFG2_DATABUS_WIDEN | INTF_CFG2_DATA_HCTL_EN;
> +               intf_cfg2 |= INTF_CFG2_DATABUS_WIDEN;
>
>         data_width = p->width;
>
> @@ -229,6 +224,14 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *ctx,
>         DPU_REG_WRITE(c, INTF_CONFIG, intf_cfg);
>         DPU_REG_WRITE(c, INTF_PANEL_FORMAT, panel_format);
>         if (ctx->cap->features & BIT(DPU_DATA_HCTL_EN)) {
> +               /*
> +                * DATA_HCTL_EN controls data timing which can be different from
> +                * video timing. It is recommended to enable it for all cases, except
> +                * if compression is enabled in 1 pixel per clock mode
> +                */
> +               if (!(p->compression_en && !p->wide_bus_en))
> +                       intf_cfg2 |= INTF_CFG2_DATA_HCTL_EN;
> +
>                 DPU_REG_WRITE(c, INTF_CONFIG2, intf_cfg2);
>                 DPU_REG_WRITE(c, INTF_DISPLAY_DATA_HCTL, display_data_hctl);
>                 DPU_REG_WRITE(c, INTF_ACTIVE_DATA_HCTL, active_data_hctl);
> 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 0bd57a32144a..6f4c87244f94 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
> @@ -33,6 +33,7 @@ struct dpu_hw_intf_timing_params {
>         u32 hsync_skew;
>
>         bool wide_bus_en;
> +       bool compression_en;
>  };
>
>  struct dpu_hw_intf_prog_fetch {
> --
> 2.40.1
>


-- 
With best wishes
Dmitry