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Message-ID: <ff150ae7-808e-9194-94d4-8976cd21c396@quicinc.com>
Date:   Mon, 31 Jan 2022 12:50:35 -0800
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Subject: Re: [PATCH] drm/msm/dp: add wide bus support
Content-Language: en-US
To:     Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
CC:     <robdclark@gmail.com>, <sean@poorly.run>, <swboyd@chromium.org>,
        <vkoul@kernel.org>, <daniel@ffwll.ch>, <airlied@linux.ie>,
        <agross@kernel.org>, <bjorn.andersson@linaro.org>,
        <quic_abhinavk@quicinc.com>, <aravindh@codeaurora.org>,
        <freedreno@lists.freedesktop.org>,
        <dri-devel@lists.freedesktop.org>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
References: <1643390945-10813-1-git-send-email-quic_khsieh@quicinc.com>
 <CAA8EJpqVAB31uzav-qMsBEBk0j2dk-qy1cRRRccCRLgJRqCS2g@mail.gmail.com>
From:   Kuogee Hsieh <quic_khsieh@quicinc.com>
In-Reply-To: <CAA8EJpqVAB31uzav-qMsBEBk0j2dk-qy1cRRRccCRLgJRqCS2g@mail.gmail.com>
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On 1/28/2022 8:59 PM, Dmitry Baryshkov wrote:
> Hi,
>
> Thank you for your patch.
>
> On Fri, 28 Jan 2022 at 20:29, Kuogee Hsieh <quic_khsieh@quicinc.com> wrote:
>> Normally, mdp will push one pixel of data per pixel clock to
>> interface to display. Wide bus feature will increase bus
>> width from 32 bits to 64 bits so that it can push two
>> pixel of data per pixel clock to interface to display.
>> This feature is pre requirement to support 4k resolution.
>>
>> Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
>> ---
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c        |  16 ++-
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h        |   2 +
>>   .../gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c   |  14 +++
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c        | 108 +++++++++++++++------
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h        |   5 +
>>   drivers/gpu/drm/msm/dp/dp_catalog.c                |  11 ++-
>>   drivers/gpu/drm/msm/dp/dp_catalog.h                |   1 +
>>   drivers/gpu/drm/msm/dp/dp_ctrl.c                   |   9 +-
>>   drivers/gpu/drm/msm/dp/dp_ctrl.h                   |   1 +
>>   drivers/gpu/drm/msm/dp/dp_display.c                |  17 ++++
>>   drivers/gpu/drm/msm/dp/dp_display.h                |   3 +
>>   drivers/gpu/drm/msm/dp/dp_parser.c                 |  26 +++++
>>   drivers/gpu/drm/msm/dp/dp_parser.h                 |   2 +
>>   drivers/gpu/drm/msm/msm_drv.h                      |   9 ++
> Can we get this split into logical chunks please?
>
>>   14 files changed, 190 insertions(+), 34 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> index 1e648db..e2fb5bc 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> @@ -199,6 +199,8 @@ struct dpu_encoder_virt {
>>
>>          struct msm_display_info disp_info;
>>
>> +       struct msm_op_info op_info;
>> +
>>          bool idle_pc_supported;
>>          struct mutex rc_lock;
>>          enum dpu_enc_rc_states rc_state;
>> @@ -217,6 +219,13 @@ static u32 dither_matrix[DITHER_MATRIX_SZ] = {
>>          15, 7, 13, 5, 3, 11, 1, 9, 12, 4, 14, 6, 0, 8, 2, 10
>>   };
>>
>> +bool dpu_encoder_is_widebus_enabled(struct drm_encoder *drm_enc)
>> +{
>> +       struct dpu_encoder_virt *dpu_enc = to_dpu_encoder_virt(drm_enc);
>> +
>> +       return dpu_enc->op_info.wide_bus_en;
>> +}
>> +
>>   static void _dpu_encoder_setup_dither(struct dpu_hw_pingpong *hw_pp, unsigned bpc)
>>   {
>>          struct dpu_hw_dither_cfg dither_cfg = { 0 };
>> @@ -2112,6 +2121,7 @@ int dpu_encoder_setup(struct drm_device *dev, struct drm_encoder *enc,
>>          struct dpu_kms *dpu_kms = to_dpu_kms(priv->kms);
>>          struct drm_encoder *drm_enc = NULL;
>>          struct dpu_encoder_virt *dpu_enc = NULL;
>> +       struct msm_op_info *op_info;
>>          int ret = 0;
>>
>>          dpu_enc = to_dpu_encoder_virt(enc);
>> @@ -2128,8 +2138,12 @@ int dpu_encoder_setup(struct drm_device *dev, struct drm_encoder *enc,
>>                  timer_setup(&dpu_enc->vsync_event_timer,
>>                                  dpu_encoder_vsync_event_handler,
>>                                  0);
>> -       else if (disp_info->intf_type == DRM_MODE_ENCODER_TMDS)
>> +       else if (disp_info->intf_type == DRM_MODE_ENCODER_TMDS) {
>>                  dpu_enc->dp = priv->dp[disp_info->h_tile_instance[0]];
>> +               op_info = &priv->op_info[disp_info->h_tile_instance[0]];
> op_info should be defined per INTF rather than per h_tile. This way
> you won't have to check for intf_type here.
>
>> +               dpu_enc->op_info = *op_info;
> So... we set this data in msm_drm_private only to copy it to
> dpu_encoder_virt? Please don't do this.
> Allow one to query the data from the DP rather than blindly copying it
> over and over again.
>
>> +
>> +       }
>>
>>          INIT_DELAYED_WORK(&dpu_enc->delayed_off_work,
>>                          dpu_encoder_off_work);
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
>> index e241914..0d73550 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.h
>> @@ -168,4 +168,6 @@ int dpu_encoder_get_linecount(struct drm_encoder *drm_enc);
>>    */
>>   int dpu_encoder_get_vsync_count(struct drm_encoder *drm_enc);
>>
>> +bool dpu_encoder_is_widebus_enabled(struct drm_encoder *drm_enc);
>> +
>>   #endif /* __DPU_ENCODER_H__ */
>> 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 ddd9d89..04ac2dc 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
>> @@ -110,6 +110,20 @@ static void drm_mode_to_intf_timing_params(
>>                  timing->v_back_porch += timing->v_front_porch;
>>                  timing->v_front_porch = 0;
>>          }
>> +
>> +       timing->wide_bus_en = dpu_encoder_is_widebus_enabled(phys_enc->parent);
>> +
>> +       /*
>> +        * for DP, divide the horizonal parameters by 2 when
>> +        * widebus is enabled
>> +        */
>> +       if (phys_enc->hw_intf->cap->type == INTF_DP && timing->wide_bus_en) {
> What about INTF_eDP?
> I suspect that intf type check is unnecessary here.
>
>> +               timing->width = timing->width >> 1;
>> +               timing->xres = timing->xres >> 1;
>> +               timing->h_back_porch = timing->h_back_porch >> 1;
>> +               timing->h_front_porch = timing->h_front_porch >> 1;
>> +               timing->hsync_pulse_width = timing->hsync_pulse_width >> 1;
>> +       }
>>   }
>>
>>   static u32 get_horizontal_total(const struct intf_timing_params *timing)
>> 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 116e2b5..f072bd5 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.c
>> @@ -33,6 +33,7 @@
>>   #define INTF_TP_COLOR1                  0x05C
>>   #define INTF_CONFIG2                    0x060
>>   #define INTF_DISPLAY_DATA_HCTL          0x064
>> +#define INTF_ACTIVE_DATA_HCTL           0x068
>>   #define INTF_FRAME_LINE_COUNT_EN        0x0A8
>>   #define INTF_FRAME_COUNT                0x0AC
>>   #define   INTF_LINE_COUNT               0x0B0
>> @@ -90,67 +91,109 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *ctx,
>>          u32 hsync_period, vsync_period;
>>          u32 display_v_start, display_v_end;
>>          u32 hsync_start_x, hsync_end_x;
>> +       u32 hsync_data_start_x, hsync_data_end_x;
>>          u32 active_h_start, active_h_end;
>>          u32 active_v_start, active_v_end;
>>          u32 active_hctl, display_hctl, hsync_ctl;
>>          u32 polarity_ctl, den_polarity, hsync_polarity, vsync_polarity;
>>          u32 panel_format;
>> -       u32 intf_cfg, intf_cfg2 = 0, display_data_hctl = 0;
>> +       u32 intf_cfg, intf_cfg2 = 0;
>> +       u32 display_data_hctl = 0, active_data_hctl = 0;
>> +       u32 data_width;
>> +       bool dp_intf = false;
>>
>>          /* read interface_cfg */
>>          intf_cfg = DPU_REG_READ(c, INTF_CONFIG);
>> +
>> +       if (ctx->cap->type == INTF_EDP || ctx->cap->type == INTF_DP)
>> +               dp_intf = true;
>> +
>>          hsync_period = p->hsync_pulse_width + p->h_back_porch + p->width +
>>          p->h_front_porch;
>>          vsync_period = p->vsync_pulse_width + p->v_back_porch + p->height +
>>          p->v_front_porch;
>>
>>          display_v_start = ((p->vsync_pulse_width + p->v_back_porch) *
>> -       hsync_period) + p->hsync_skew;
>> +                       hsync_period) + p->hsync_skew;
> Unnecessary whitespace changes complicate reviewing. I'll try groking
> this piece of code later.
>
>>          display_v_end = ((vsync_period - p->v_front_porch) * hsync_period) +
>> -       p->hsync_skew - 1;
>> +                       p->hsync_skew - 1;
>> +
>> +       hsync_ctl = (hsync_period << 16) | p->hsync_pulse_width;
>>
>>          hsync_start_x = p->h_back_porch + p->hsync_pulse_width;
>>          hsync_end_x = hsync_period - p->h_front_porch - 1;
>>
>> -       if (p->width != p->xres) {
>> -               active_h_start = hsync_start_x;
>> -               active_h_end = active_h_start + p->xres - 1;
>> -       } else {
>> -               active_h_start = 0;
>> -               active_h_end = 0;
>> -       }
>> +       /*
>> +        * 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 |= BIT(4);
>>
>> -       if (p->height != p->yres) {
>> -               active_v_start = display_v_start;
>> -               active_v_end = active_v_start + (p->yres * hsync_period) - 1;
>> -       } else {
>> -               active_v_start = 0;
>> -               active_v_end = 0;
>> -       }
>> +       if (p->wide_bus_en)
>> +               intf_cfg2 |= BIT(0);
>> +
>> +       /*
>> +        * If widebus is disabled:
>> +        * For uncompressed stream, the data is valid for the entire active
>> +        * window period.
>> +        * For compressed stream, data is valid for a shorter time period
>> +        * inside the active window depending on the compression ratio.
>> +        *
>> +        * If widebus is enabled:
>> +        * For uncompressed stream, data is valid for only half the active
>> +        * window, since the data rate is doubled in this mode.
>> +        * p->width holds the adjusted width for DP but unadjusted width for DSI
>> +        * For compressed stream, data validity window needs to be adjusted for
>> +        * compression ratio and then further halved.
>> +        */
>> +       data_width = p->width;
>> +
>> +       if (p->compression_en) {
>> +               data_width = DIV_ROUND_UP(p->dce_bytes_per_line, 3);
>>
>> -       if (active_h_end) {
>> -               active_hctl = (active_h_end << 16) | active_h_start;
>> -               intf_cfg |= BIT(29);    /* ACTIVE_H_ENABLE */
>> +               if (p->wide_bus_en)
>> +                       data_width >>= 1;
>> +       } else if (!dp_intf && p->wide_bus_en) {
>> +               data_width = p->width >> 1;
>>          } else {
>> -               active_hctl = 0;
>> +               data_width = p->width;
>>          }
>>
>> -       if (active_v_end)
>> -               intf_cfg |= BIT(30); /* ACTIVE_V_ENABLE */
>> +       hsync_data_start_x = hsync_start_x;
>> +       hsync_data_end_x =  hsync_start_x + data_width - 1;
>>
>> -       hsync_ctl = (hsync_period << 16) | p->hsync_pulse_width;
>>          display_hctl = (hsync_end_x << 16) | hsync_start_x;
>> +       display_data_hctl = (hsync_data_end_x << 16) | hsync_data_start_x;
>>
>> -       if (ctx->cap->type == INTF_EDP || ctx->cap->type == INTF_DP) {
>> -               active_h_start = hsync_start_x;
>> -               active_h_end = active_h_start + p->xres - 1;
>> -               active_v_start = display_v_start;
>> -               active_v_end = active_v_start + (p->yres * hsync_period) - 1;
>> -
>> +       if (dp_intf) {
>> +               // DP timing adjustment
>>                  display_v_start += p->hsync_pulse_width + p->h_back_porch;
>> +               display_v_end   -= p->h_front_porch;
>> +       }
>>
>> -               active_hctl = (active_h_end << 16) | active_h_start;
>> +
>> +       active_h_start = hsync_start_x;
>> +       active_h_end = active_h_start + p->xres - 1;
>> +
>> +       active_v_start = display_v_start;
>> +       active_v_end = active_v_start + (p->yres * hsync_period) - 1;
>> +
>> +       intf_cfg |= BIT(29);    /* ACTIVE_H_ENABLE */
>> +       intf_cfg |= BIT(30);    /* ACTIVE_V_ENABLE */
>> +
>> +       active_hctl = (active_h_end << 16) | active_h_start;
>> +
>> +       if (dp_intf) {
>>                  display_hctl = active_hctl;
>> +               if (p->compression_en) {
> I assume that compression_en is a part of DSC support for the DP, isn't it?
> If so, it should definitely come as a separate patch.
>
>> +                       active_data_hctl = (hsync_start_x +
>> +                                       p->extra_dto_cycles) << 16;
>> +                       active_data_hctl += hsync_start_x;
>> +
>> +                       display_data_hctl = active_data_hctl;
>> +               }
>>          }
>>
>>          den_polarity = 0;
>> @@ -204,6 +247,9 @@ static void dpu_hw_intf_setup_timing_engine(struct dpu_hw_intf *ctx,
>>          DPU_REG_WRITE(c, INTF_FRAME_LINE_COUNT_EN, 0x3);
>>          DPU_REG_WRITE(c, INTF_CONFIG, intf_cfg);
>>          DPU_REG_WRITE(c, INTF_PANEL_FORMAT, panel_format);
>> +       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);
> Are these registers present on all supported hardware (like sdm845)?
> Does msm8998 support them? msm8996?

no, i  think they are start from sm8250 (Kona).

But they should be no effects after write.

>>   }
>>
>>   static void dpu_hw_intf_enable_timing_engine(
>> 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 3568be8..8fc71ce 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h
>> @@ -30,6 +30,11 @@ struct intf_timing_params {
>>          u32 border_clr;
>>          u32 underflow_clr;
>>          u32 hsync_skew;
>> +
>> +       bool wide_bus_en;
>> +       bool compression_en;
>> +       u32 extra_dto_cycles;   /* for DP only */
>> +       u32 dce_bytes_per_line;
> All compression-related items should come in a separate patch.
>
>>   };
>>
>>   struct intf_prog_fetch {
>> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
>> index 6d6850e..d738e2e 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_catalog.c
>> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
>> @@ -745,6 +745,7 @@ int dp_catalog_panel_timing_cfg(struct dp_catalog *dp_catalog)
>>   {
>>          struct dp_catalog_private *catalog = container_of(dp_catalog,
>>                                  struct dp_catalog_private, dp_catalog);
>> +       u32 reg;
>>
>>          dp_write_link(catalog, REG_DP_TOTAL_HOR_VER,
>>                                  dp_catalog->total);
>> @@ -753,7 +754,15 @@ int dp_catalog_panel_timing_cfg(struct dp_catalog *dp_catalog)
>>          dp_write_link(catalog, REG_DP_HSYNC_VSYNC_WIDTH_POLARITY,
>>                                  dp_catalog->width_blanking);
>>          dp_write_link(catalog, REG_DP_ACTIVE_HOR_VER, dp_catalog->dp_active);
>> -       dp_write_p0(catalog, MMSS_DP_INTF_CONFIG, 0);
>> +
>> +        reg = dp_read_p0(catalog, MMSS_DP_INTF_CONFIG);
>> +
>> +        if (dp_catalog->wide_bus_en)
>> +                reg |= BIT(4);
>> +        else
>> +                reg &= ~BIT(4);
>> +
>> +        dp_write_p0(catalog, MMSS_DP_INTF_CONFIG, reg);
>>          return 0;
>>   }
>>
>> diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.h b/drivers/gpu/drm/msm/dp/dp_catalog.h
>> index 7dea101..6ca563f 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_catalog.h
>> +++ b/drivers/gpu/drm/msm/dp/dp_catalog.h
>> @@ -70,6 +70,7 @@ struct dp_catalog {
>>          enum dp_catalog_audio_sdp_type sdp_type;
>>          enum dp_catalog_audio_header_type sdp_header;
>>          u32 audio_data;
>> +       bool wide_bus_en;
>>   };
>>
>>   /* Debug module */
>> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
>> index 53ad3af..401ae57 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
>> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
>> @@ -1812,6 +1812,7 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl)
>>          int ret = 0;
>>          bool mainlink_ready = false;
>>          struct dp_ctrl_private *ctrl;
>> +       u32 pixel_rate_orig;
>>
>>          if (!dp_ctrl)
>>                  return -EINVAL;
>> @@ -1820,6 +1821,10 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl)
>>
>>          ctrl->dp_ctrl.pixel_rate = ctrl->panel->dp_mode.drm_mode.clock;
>>
>> +       pixel_rate_orig = ctrl->dp_ctrl.pixel_rate;
>> +       if (dp_ctrl->wide_bus_en)
>> +               ctrl->dp_ctrl.pixel_rate >>= 1;
>> +
>>          drm_dbg_dp((struct drm_device *)NULL, "rate=%d, num_lanes=%d, pixel_rate=%d\n",
>>                  ctrl->link->link_params.rate,
>>                  ctrl->link->link_params.num_lanes, ctrl->dp_ctrl.pixel_rate);
>> @@ -1855,11 +1860,13 @@ int dp_ctrl_on_stream(struct dp_ctrl *dp_ctrl)
>>           */
>>          reinit_completion(&ctrl->video_comp);
>>
>> +       ctrl->catalog->wide_bus_en = dp_ctrl->wide_bus_en;
> Can you limit the DP's knowledge of wide_bus_en to a single place
> (e.g. only in dp_catalog or in dp_ctrl)? Just copying the data bit
> means that we have two places which must be kept in sync.
>
>> +
>>          dp_ctrl_configure_source_params(ctrl);
>>
>>          dp_catalog_ctrl_config_msa(ctrl->catalog,
>>                  ctrl->link->link_params.rate,
>> -               ctrl->dp_ctrl.pixel_rate, dp_ctrl_use_fixed_nvid(ctrl));
>> +               pixel_rate_orig, dp_ctrl_use_fixed_nvid(ctrl));
>>
>>          dp_ctrl_setup_tr_unit(ctrl);
>>
>> diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.h b/drivers/gpu/drm/msm/dp/dp_ctrl.h
>> index 2433edb..4dff44d 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_ctrl.h
>> +++ b/drivers/gpu/drm/msm/dp/dp_ctrl.h
>> @@ -17,6 +17,7 @@ struct dp_ctrl {
>>          bool orientation;
>>          atomic_t aborted;
>>          u32 pixel_rate;
>> +       bool wide_bus_en;
>>   };
>>
>>   int dp_ctrl_on_link(struct dp_ctrl *dp_ctrl);
>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
>> index f89f3ed..924c9e2 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_display.c
>> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
>> @@ -873,6 +873,8 @@ static int dp_display_enable(struct dp_display_private *dp, u32 data)
>>                  return 0;
>>          }
>>
>> +       dp->ctrl->wide_bus_en = dp_display->wide_bus_en;
> Ugh. This adds a third place. dp_display, dp_ctrl and dp_catalog. Too
> much for a single bit.
>
>> +
>>          rc = dp_ctrl_on_stream(dp->ctrl);
>>          if (!rc)
>>                  dp_display->power_on = true;
>> @@ -1004,6 +1006,8 @@ int dp_display_get_modes(struct msm_dp *dp,
>>                  dp->connector, dp_mode);
>>          if (dp_mode->drm_mode.clock)
>>                  dp->max_pclk_khz = dp_mode->drm_mode.clock;
>> +
>> +       DRM_DEBUG_DP("wide_bus_en=%d\n", dp->wide_bus_en);
>>          return ret;
>>   }
>>
>> @@ -1503,6 +1507,8 @@ int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev,
>>   {
>>          struct msm_drm_private *priv;
>>          struct dp_display_private *dp_priv;
>> +       struct msm_op_info *op;
>> +       struct dp_display_private *dp;
>>          int ret;
>>
>>          if (WARN_ON(!encoder) || WARN_ON(!dp_display) || WARN_ON(!dev))
>> @@ -1545,6 +1551,17 @@ int msm_dp_modeset_init(struct msm_dp *dp_display, struct drm_device *dev,
>>
>>          priv->bridges[priv->num_bridges++] = dp_display->bridge;
>>
>> +       dp = container_of(dp_display, struct dp_display_private, dp_display);
>> +
>> +       dp_display->wide_bus_en = dp->parser->has_widebus;
>> +       dp_display->compression_en = dp->parser->has_compression;
>> +
>> +       op = &priv->op_info[dp->id];
>> +       op->wide_bus_en = dp_display->wide_bus_en;
>> +       op->compression_en = dp_display->compression_en;
>> +
>> +       drm_dbg_dp(dp->drm_dev, "id=%d widebus=%d compression=%d\n",
>> +                       dp->id, op->wide_bus_en, op->compression_en);
>>          return 0;
>>   }
>>
>> diff --git a/drivers/gpu/drm/msm/dp/dp_display.h b/drivers/gpu/drm/msm/dp/dp_display.h
>> index e3adcd5..b1057cb 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_display.h
>> +++ b/drivers/gpu/drm/msm/dp/dp_display.h
>> @@ -24,6 +24,9 @@ struct msm_dp {
>>
>>          hdmi_codec_plugged_cb plugged_cb;
>>
>> +       bool wide_bus_en;
>> +       bool compression_en;
>> +
>>          u32 max_pclk_khz;
>>
>>          u32 max_dp_lanes;
>> diff --git a/drivers/gpu/drm/msm/dp/dp_parser.c b/drivers/gpu/drm/msm/dp/dp_parser.c
>> index e74012d..fd48eb8 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_parser.c
>> +++ b/drivers/gpu/drm/msm/dp/dp_parser.c
>> @@ -286,6 +286,28 @@ static int dp_parser_find_panel(struct dp_parser *parser)
>>          return 0;
>>   }
>>
>> +static void dp_parser_compression(struct dp_parser *parser)
>> +{
>> +       struct device *dev = &parser->pdev->dev;
>> +
>> +       parser->has_compression = of_property_read_bool(dev->of_node,
>> +                               "qcom,compression-enable");
>> +
>> +       DRM_DEBUG_DP("compression parsing successful. compression:%d\n",
>> +                       parser->has_compression);
>> +}
>> +
>> +static void dp_parser_widebus(struct dp_parser *parser)
>> +{
>> +       struct device *dev = &parser->pdev->dev;
>> +
>> +       parser->has_widebus = of_property_read_bool(dev->of_node,
>> +                               "qcom,widebus-enable");
>> +
>> +       DRM_DEBUG_DP("widebus parsing successful. widebus:%d\n",
>> +                       parser->has_widebus);
>> +}
> All new properties should be described in the dt-bindings document.
>
> However I have a bigger question here. Who and how decides whether
> compression or widebus should be enabled?
>
> Should we enable widebus for all generations that support it? If so,
> this should be a part of msm_dp_config rather than the DTS property.
> And I'm completely puzzled about the compression-enable here.
>
>
>> +
>>   static int dp_parser_parse(struct dp_parser *parser, int connector_type)
>>   {
>>          int rc = 0;
>> @@ -319,6 +341,10 @@ static int dp_parser_parse(struct dp_parser *parser, int connector_type)
>>           */
>>          parser->regulator_cfg = &sdm845_dp_reg_cfg;
>>
>> +        dp_parser_widebus(parser);
>> +
>> +        dp_parser_compression(parser);
>> +
>>          return 0;
>>   }
>>
>> diff --git a/drivers/gpu/drm/msm/dp/dp_parser.h b/drivers/gpu/drm/msm/dp/dp_parser.h
>> index 3172da0..7531fe2 100644
>> --- a/drivers/gpu/drm/msm/dp/dp_parser.h
>> +++ b/drivers/gpu/drm/msm/dp/dp_parser.h
>> @@ -123,6 +123,8 @@ struct dp_parser {
>>          struct dp_display_data disp_data;
>>          const struct dp_regulator_cfg *regulator_cfg;
>>          u32 max_dp_lanes;
>> +       bool has_widebus;
>> +       bool has_compression;
>>          struct drm_bridge *panel_bridge;
>>
>>          int (*parse)(struct dp_parser *parser, int connector_type);
>> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
>> index d7574e6..1a5f3e9 100644
>> --- a/drivers/gpu/drm/msm/msm_drv.h
>> +++ b/drivers/gpu/drm/msm/msm_drv.h
>> @@ -127,6 +127,11 @@ struct msm_display_info {
>>          bool is_te_using_watchdog_timer;
>>   };
>>
>> +struct msm_op_info {
>> +       bool wide_bus_en;
>> +       bool compression_en;
>> +};
>> +
>>   /* Commit/Event thread specific structure */
>>   struct msm_drm_thread {
>>          struct drm_device *dev;
>> @@ -156,6 +161,8 @@ struct msm_drm_private {
>>
>>          struct msm_dp *dp[MSM_DP_CONTROLLER_COUNT];
>>
>> +       struct msm_op_info op_info[MSM_DP_CONTROLLER_COUNT];
>> +
> As I said before, it should be INTF_MAX. Or you can retrieve it from
> priv->dp as needed instead.
>
>>          /* when we have more than one 'msm_gpu' these need to be an array: */
>>          struct msm_gpu *gpu;
>>
>> @@ -338,6 +345,8 @@ int msm_hdmi_modeset_init(struct hdmi *hdmi, struct drm_device *dev,
>>   void __init msm_hdmi_register(void);
>>   void __exit msm_hdmi_unregister(void);
>>
>> +struct msm_dp;
>> +
>>   struct msm_dsi;
>>   #ifdef CONFIG_DRM_MSM_DSI
>>   int dsi_dev_attach(struct platform_device *pdev);
>> --
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>> a Linux Foundation Collaborative Project
>>
>