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

Jessica Zhang quic_jesszhan at quicinc.com
Mon Aug 7 22:21:41 UTC 2023



On 8/2/2023 12:39 PM, Marijn Suijten wrote:
> On 2023-08-02 11:08:49, Jessica Zhang 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 at quicinc.com>
>> ---
>>   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]);
> 
> This inconsistency really is killing.  wide_bus vs widebus, and one
> function has an is_ while the other does not.

Hi Marijn,

Acked. Will change the DSI function name to match DP.

> 
>>   
>>   	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);
>> +	}
>>   
>>   	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 */
> 
> Any clue why these weren't just bool types?  These suffix-comments also
> aren't adhering to the kerneldoc format, or is there a different
> variant?

It seems that the `u8` declaration and comment docs were meant to mirror 
the other dpu_hw_intf_* structs [1]

[1] 
https://elixir.bootlin.com/linux/v6.5-rc5/source/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_intf.h#L44

> 
>>   };
>>   
>>   /**
>> 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;
>> +}
> 
> Only this default inline implementation is defined, but the function is
> declared in this commit.  Since there's no real functional
> implementation yet your commit should clarify that it comes later (in a
> followup commit in the same series?  I can't know because I am reviewing
> this series linearly from start to finish...) or reorder the patches so
> that this lack of clarity is circumvented entirely.

This was so that there wouldn't be a compiler error in cases where 
CONFIG_MSM_DSI=n (since DPU support is added before DSI support).

Thanks,

Jessica Zhang

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


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