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Message-ID: <91bc6348-2030-85dd-1492-1609b392793f@linaro.org>
Date:   Fri, 14 Jul 2023 04:23:55 +0300
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Subject: Re: [PATCH v2] drm/msm/dsi: Enable DATABUS_WIDEN for DSI command mode
Content-Language: en-GB
To:     Jessica Zhang <quic_jesszhan@quicinc.com>,
        Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>
Cc:     quic_abhinavk@quicinc.com, linux-arm-msm@vger.kernel.org,
        dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
References: <20230713-add-widebus-support-v2-1-ad0added17b6@quicinc.com>
From:   Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
In-Reply-To: <20230713-add-widebus-support-v2-1-ad0added17b6@quicinc.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
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Precedence: bulk

On 14/07/2023 03:21, Jessica Zhang wrote:
> DSI 6G v2.5.x+ and DPU 7.x+ support a data-bus widen mode that allows DSI
> to send 48 bits of compressed data per pclk instead of 24.
> 
> For all chipsets that support this mode, enable it whenever DSC is
> enabled as recommended by the hardware programming guide.
> 
> Only enable this for command mode as we are currently unable to validate
> it for video mode.
> 
> Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
> ---
> Note: The dsi.xml.h changes were generated using the headergen2 script in
> envytools [2], but the changes to the copyright and rules-ng-ng source file
> paths were dropped.

Separate commit please, so that it can be replaced by headers sync with 
Mesa3d.

> 
> [1] https://patchwork.freedesktop.org/series/120580/
> [2] https://github.com/freedreno/envytools/
> 
> --
> Changes in v2:
> - Rebased on top of "drm/msm/dpu: Re-introduce dpu core revision"
> - Squashed all commits to avoid breaking feature if the series is only partially applied

No. Please unsquash it. Please design the series so that the patches 
work even if it is only partially applied.

> - Moved DATABUS_WIDEN bit setting to dsi_ctr_enable() (Marijn)
> - Have DPU check if wide bus is requested by output driver (Dmitry)
> - Introduced bytes_per_pclk variable for dsi_timing_setup() hdisplay adjustment (Marijn)
> - Link to v1: https://lore.kernel.org/r/20230525-add-widebus-support-v1-0-c7069f2efca1@quicinc.com
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c        | 10 ++++++----
>   .../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/dsi/dsi.c                      |  5 +++++
>   drivers/gpu/drm/msm/dsi/dsi.h                      |  1 +
>   drivers/gpu/drm/msm/dsi/dsi.xml.h                  |  1 +
>   drivers/gpu/drm/msm/dsi/dsi_host.c                 | 23 +++++++++++++++++++++-
>   drivers/gpu/drm/msm/msm_drv.h                      |  6 ++++++
>   9 files changed, 48 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 f0a2a1dca741..6aed63c06c1d 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -2411,6 +2411,7 @@ struct drm_encoder *dpu_encoder_init(struct drm_device *dev,
>   	struct dpu_kms *dpu_kms = to_dpu_kms(priv->kms);
>   	struct drm_encoder *drm_enc = NULL;
>   	struct dpu_encoder_virt *dpu_enc = NULL;
> +	int index = disp_info->h_tile_instance[0];
>   	int ret = 0;
>   
>   	dpu_enc = devm_kzalloc(dev->dev, sizeof(*dpu_enc), GFP_KERNEL);
> @@ -2439,13 +2440,14 @@ struct drm_encoder *dpu_encoder_init(struct drm_device *dev,
>   	timer_setup(&dpu_enc->frame_done_timer,
>   			dpu_encoder_frame_done_timeout, 0);
>   
> -	if (disp_info->intf_type == INTF_DSI)
> +	if (disp_info->intf_type == INTF_DSI) {
>   		timer_setup(&dpu_enc->vsync_event_timer,
>   				dpu_encoder_vsync_event_handler,

While you are touching this part, could you please drop 
dpu_encoder_vsync_event_handler() and 
dpu_encoder_vsync_event_work_handler(), they are useless?

>   				0);
> -	else 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]]);
> +		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]);
> +	}
>   
>   	INIT_DELAYED_WORK(&dpu_enc->delayed_off_work,
>   			dpu_encoder_off_work);
> 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);
> +	}
>   
>   	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,
>   	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/dsi/dsi.c b/drivers/gpu/drm/msm/dsi/dsi.c
> index baab79ab6e74..e3cc06c94397 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi.c
> @@ -17,6 +17,11 @@ struct drm_dsc_config *msm_dsi_get_dsc_config(struct msm_dsi *msm_dsi)
>   	return msm_dsi_host_get_dsc_config(msm_dsi->host);
>   }
>   
> +bool msm_dsi_is_widebus_enabled(struct msm_dsi *msm_dsi)
> +{
> +	return msm_dsi_host_is_widebus_supported(msm_dsi->host);

This is incorrect. It will enable widebus even for non-DSC cases.

> +}
> +
>   static int dsi_get_phy(struct msm_dsi *msm_dsi)
>   {
>   	struct platform_device *pdev = msm_dsi->pdev;
> diff --git a/drivers/gpu/drm/msm/dsi/dsi.h b/drivers/gpu/drm/msm/dsi/dsi.h
> index bd3763a5d723..219a9f756759 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi.h
> +++ b/drivers/gpu/drm/msm/dsi/dsi.h
> @@ -134,6 +134,7 @@ int dsi_calc_clk_rate_6g(struct msm_dsi_host *msm_host, bool is_bonded_dsi);
>   void msm_dsi_host_snapshot(struct msm_disp_state *disp_state, struct mipi_dsi_host *host);
>   void msm_dsi_host_test_pattern_en(struct mipi_dsi_host *host);
>   struct drm_dsc_config *msm_dsi_host_get_dsc_config(struct mipi_dsi_host *host);
> +bool msm_dsi_host_is_widebus_supported(struct mipi_dsi_host *host);
>   
>   /* dsi phy */
>   struct msm_dsi_phy;
> diff --git a/drivers/gpu/drm/msm/dsi/dsi.xml.h b/drivers/gpu/drm/msm/dsi/dsi.xml.h
> index a4a154601114..2a7d980e12c3 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi.xml.h
> +++ b/drivers/gpu/drm/msm/dsi/dsi.xml.h
> @@ -664,6 +664,7 @@ static inline uint32_t DSI_CMD_MODE_MDP_CTRL2_INPUT_RGB_SWAP(enum dsi_rgb_swap v
>   	return ((val) << DSI_CMD_MODE_MDP_CTRL2_INPUT_RGB_SWAP__SHIFT) & DSI_CMD_MODE_MDP_CTRL2_INPUT_RGB_SWAP__MASK;
>   }
>   #define DSI_CMD_MODE_MDP_CTRL2_BURST_MODE			0x00010000
> +#define DSI_CMD_MODE_MDP_CTRL2_DATABUS_WIDEN			0x00100000
>   
>   #define REG_DSI_CMD_MODE_MDP_STREAM2_CTRL			0x000001b8
>   #define DSI_CMD_MODE_MDP_STREAM2_CTRL_DATA_TYPE__MASK		0x0000003f
> diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
> index 645927214871..6ea3476acf0d 100644
> --- a/drivers/gpu/drm/msm/dsi/dsi_host.c
> +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
> @@ -710,6 +710,14 @@ static void dsi_ctrl_disable(struct msm_dsi_host *msm_host)
>   	dsi_write(msm_host, REG_DSI_CTRL, 0);
>   }
>   
> +bool msm_dsi_host_is_widebus_supported(struct mipi_dsi_host *host)
> +{
> +	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
> +
> +	return msm_host->cfg_hnd->major == MSM_DSI_VER_MAJOR_6G &&
> +			msm_host->cfg_hnd->minor >= MSM_DSI_6G_VER_MINOR_V2_5_0;

Would it be better to push it to the config data, like we did for DP?

> +}
> +
>   static void dsi_ctrl_enable(struct msm_dsi_host *msm_host,
>   			struct msm_dsi_phy_shared_timings *phy_shared_timings, struct msm_dsi_phy *phy)
>   {
> @@ -757,6 +765,11 @@ static void dsi_ctrl_enable(struct msm_dsi_host *msm_host,
>   		    msm_host->cfg_hnd->minor >= MSM_DSI_6G_VER_MINOR_V1_3) {
>   			data = dsi_read(msm_host, REG_DSI_CMD_MODE_MDP_CTRL2);
>   			data |= DSI_CMD_MODE_MDP_CTRL2_BURST_MODE;
> +
> +			/* TODO: Allow for video-mode support once tested/fixed */
> +			if (msm_host->cfg_hnd->minor >= MSM_DSI_6G_VER_MINOR_V2_5_0 && msm_host->dsc)

msm_dsi_is_widebus_enabled() && msm_host->dsc

> +				data |= DSI_CMD_MODE_MDP_CTRL2_DATABUS_WIDEN;
> +
>   			dsi_write(msm_host, REG_DSI_CMD_MODE_MDP_CTRL2, data);
>   		}
>   	}
> @@ -894,6 +907,7 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>   	u32 hdisplay = mode->hdisplay;
>   	u32 wc;
>   	int ret;
> +	bool widebus_supported = msm_dsi_host_is_widebus_supported(&msm_host->base);

s/supported/enabled for this function.

>   
>   	DBG("");
>   
> @@ -914,6 +928,7 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>   
>   	if (msm_host->dsc) {
>   		struct drm_dsc_config *dsc = msm_host->dsc;
> +		u32 bytes_per_pclk;
>   
>   		/* update dsc params with timing params */
>   		if (!dsc || !mode->hdisplay || !mode->vdisplay) {
> @@ -937,7 +952,13 @@ static void dsi_timing_setup(struct msm_dsi_host *msm_host, bool is_bonded_dsi)
>   		 * pulse width same
>   		 */
>   		h_total -= hdisplay;
> -		hdisplay = DIV_ROUND_UP(msm_dsc_get_bytes_per_line(msm_host->dsc), 3);
> +		if (widebus_supported && !(msm_host->mode_flags & MIPI_DSI_MODE_VIDEO))
> +			bytes_per_pclk = 6;
> +		else
> +			bytes_per_pclk = 3;
> +
> +		hdisplay = DIV_ROUND_UP(msm_dsc_get_bytes_per_line(msm_host->dsc), bytes_per_pclk);
> +
>   		h_total += hdisplay;
>   		ha_end = ha_start + hdisplay;
>   	}
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index 9d9d5e009163..7ff56d09014c 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)
> @@ -374,6 +375,11 @@ 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;
> +}
> +
>   static inline struct drm_dsc_config *msm_dsi_get_dsc_config(struct msm_dsi *msm_dsi)
>   {
>   	return NULL;
> 
> ---
> base-commit: 9445fc2942a890e84c74e170ebd7dfb9566e3357
> change-id: 20230525-add-widebus-support-f785546ee751
> 
> Best regards,

-- 
With best wishes
Dmitry