[v1] drm/msm/disp/dpu1: add color management support for the crtc

  Add color management support for the crtc provided there are
enough dspps that can be allocated from the catalogue.

Changes in v1:
- cache color enabled state in the dpu crtc obj (Dmitry)
- simplify dspp allocation while creating crtc (Dmitry)
- register for color when crtc is created (Dmitry)

Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    |  5 +--
 drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h    |  6 ++--
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c |  7 ++--
 drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c     | 53 ++++++++++++++++++++++++++++-
 4 files changed, 64 insertions(+), 7 deletions(-)
  

On 11/11/2022 16:57, Kalyan Thota wrote:
> Add color management support for the crtc provided there are
> enough dspps that can be allocated from the catalogue.
> 
> Changes in v1:
> - cache color enabled state in the dpu crtc obj (Dmitry)
> - simplify dspp allocation while creating crtc (Dmitry)
> - register for color when crtc is created (Dmitry)
> 
> Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
> ---
>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    |  5 +--
>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h    |  6 ++--
>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c |  7 ++--
>   drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c     | 53 ++++++++++++++++++++++++++++-
>   4 files changed, 64 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> index 4170fbe..ca4c3b3 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
> @@ -1571,7 +1571,7 @@ static const struct drm_crtc_helper_funcs dpu_crtc_helper_funcs = {
>   
>   /* initialize crtc */
>   struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct drm_plane *plane,
> -				struct drm_plane *cursor)
> +				struct drm_plane *cursor, unsigned long features)
>   {
>   	struct drm_crtc *crtc = NULL;
>   	struct dpu_crtc *dpu_crtc = NULL;
> @@ -1583,6 +1583,7 @@ struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct drm_plane *plane,
>   
>   	crtc = &dpu_crtc->base;
>   	crtc->dev = dev;
> +	dpu_crtc->color_enabled = features & BIT(DPU_DSPP_PCC);
>   
>   	spin_lock_init(&dpu_crtc->spin_lock);
>   	atomic_set(&dpu_crtc->frame_pending, 0);
> @@ -1604,7 +1605,7 @@ struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct drm_plane *plane,
>   
>   	drm_crtc_helper_add(crtc, &dpu_crtc_helper_funcs);
>   
> -	drm_crtc_enable_color_mgmt(crtc, 0, true, 0);
> +	drm_crtc_enable_color_mgmt(crtc, 0, dpu_crtc->color_enabled, 0);
>   
>   	/* save user friendly CRTC name for later */
>   	snprintf(dpu_crtc->name, DPU_CRTC_NAME_SIZE, "crtc%u", crtc->base.id);
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
> index 539b68b..342f9ae 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
> @@ -136,6 +136,7 @@ struct dpu_crtc_frame_event {
>    * @enabled       : whether the DPU CRTC is currently enabled. updated in the
>    *                  commit-thread, not state-swap time which is earlier, so
>    *                  safe to make decisions on during VBLANK on/off work
> + * @color_enabled : whether crtc supports color management
>    * @feature_list  : list of color processing features supported on a crtc
>    * @active_list   : list of color processing features are active
>    * @dirty_list    : list of color processing features are dirty
> @@ -164,7 +165,7 @@ struct dpu_crtc {
>   	u64 play_count;
>   	ktime_t vblank_cb_time;
>   	bool enabled;
> -
> +	bool color_enabled;
>   	struct list_head feature_list;
>   	struct list_head active_list;
>   	struct list_head dirty_list;
> @@ -269,10 +270,11 @@ void dpu_crtc_complete_commit(struct drm_crtc *crtc);
>    * @dev: dpu device
>    * @plane: base plane
>    * @cursor: cursor plane
> + * @features: color features
>    * @Return: new crtc object or error
>    */
>   struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct drm_plane *plane,
> -			       struct drm_plane *cursor);
> +			       struct drm_plane *cursor, unsigned long features);
>   
>   /**
>    * dpu_crtc_register_custom_event - api for enabling/disabling crtc event
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> index c9058aa..d72edb8 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
> @@ -579,6 +579,7 @@ bool dpu_encoder_use_dsc_merge(struct drm_encoder *drm_enc)
>   static struct msm_display_topology dpu_encoder_get_topology(
>   			struct dpu_encoder_virt *dpu_enc,
>   			struct dpu_kms *dpu_kms,
> +			struct dpu_crtc *dpu_crtc,
>   			struct drm_display_mode *mode)
>   {
>   	struct msm_display_topology topology = {0};
> @@ -607,7 +608,7 @@ static struct msm_display_topology dpu_encoder_get_topology(
>   	else
>   		topology.num_lm = (mode->hdisplay > MAX_HDISPLAY_SPLIT) ? 2 : 1;
>   
> -	if (dpu_enc->disp_info.intf_type == DRM_MODE_ENCODER_DSI) {
> +	if (dpu_crtc->color_enabled) {
>   		if (dpu_kms->catalog->dspp &&
>   			(dpu_kms->catalog->dspp_count >= topology.num_lm))
>   			topology.num_dspp = topology.num_lm;
> @@ -642,6 +643,7 @@ static int dpu_encoder_virt_atomic_check(
>   	struct drm_display_mode *adj_mode;
>   	struct msm_display_topology topology;
>   	struct dpu_global_state *global_state;
> +	struct dpu_crtc *dpu_crtc;
>   	int i = 0;
>   	int ret = 0;
>   
> @@ -652,6 +654,7 @@ static int dpu_encoder_virt_atomic_check(
>   	}
>   
>   	dpu_enc = to_dpu_encoder_virt(drm_enc);
> +	dpu_crtc = to_dpu_crtc(crtc_state->crtc);
>   	DPU_DEBUG_ENC(dpu_enc, "\n");
>   
>   	priv = drm_enc->dev->dev_private;
> @@ -677,7 +680,7 @@ static int dpu_encoder_virt_atomic_check(
>   		}
>   	}
>   
> -	topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, adj_mode);
> +	topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, dpu_crtc, adj_mode);
>   
>   	/* Reserve dynamic resources now. */
>   	if (!ret) {
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> index 0709da2..ce6f5e6 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
> @@ -734,7 +734,54 @@ static int _dpu_kms_setup_displays(struct drm_device *dev,
>   	return rc;
>   }
>   
> +/**
> + * _dpu_kms_populate_dspp_features - Evaluate how many dspps pairs can be facilitated
> +                                     to enable color features for encoder and assign
> +				     color features prefering primary

preferring

> + * @dpu_kms:    Pointer to dpu kms structure
> + * @features:   Pointer to feature array
> + *
> + * Baring single entry, if atleast 2 dspps are available in the catalogue,

at least

> + * then color can be enabled for that crtc
> + */
> +static void _dpu_kms_populate_dspp_features(struct dpu_kms *dpu_kms,
> +	unsigned long *features)
> +{
> +	struct drm_encoder *encoder;
> +	u32 external_enc_mask = 0;
> +	u32 num_dspps = dpu_kms->catalog->dspp_count;
> +
> +	if (!num_dspps)
> +		return;
> +	else if (num_dspps > 1)
> +		num_dspps /= 2;
> +
> +	/* Ensure all primary encoders get first allocation of color */
> +	drm_for_each_encoder(encoder, dpu_kms->dev) {
> +		if(dpu_encoder_is_primary(encoder)) {
> +			if (num_dspps) {
> +				features[encoder->index] = dpu_kms->catalog->dspp->features;
> +				num_dspps--;
> +			}
> +		} else if(dpu_encoder_is_external(encoder)) {
> +			external_enc_mask |= drm_encoder_mask(encoder);
> +		}
> +	}
> +
> +	if(!num_dspps)
> +		return;
> +
> +	/* Allocate color for external encoders after primary */

Please. No "primary" encoders. You already have sense of internal vs 
external, plugable, or which ever way you would like to call them. You 
don't need to add another safety check, do you?

> +	drm_for_each_encoder_mask(encoder, dpu_kms->dev, external_enc_mask) {
> +		if (num_dspps) {
> +			features[encoder->index] = dpu_kms->catalog->dspp->features;
> +			num_dspps--;
> +		}
> +	}
> +}
> +
>   #define MAX_PLANES 20
> +#define MAX_ENCODERS 10
>   static int _dpu_kms_drm_obj_init(struct dpu_kms *dpu_kms)
>   {
>   	struct drm_device *dev;
> @@ -749,6 +796,8 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms *dpu_kms)
>   
>   	int primary_planes_idx = 0, cursor_planes_idx = 0, i, ret;
>   	int max_crtc_count;
> +	unsigned long features[MAX_ENCODERS] = {0};
> +
>   	dev = dpu_kms->dev;
>   	priv = dev->dev_private;
>   	catalog = dpu_kms->catalog;
> @@ -798,12 +847,14 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms *dpu_kms)
>   	}
>   
>   	max_crtc_count = min(max_crtc_count, primary_planes_idx);
> +	_dpu_kms_populate_dspp_features(dpu_kms, features);
>   
>   	/* Create one CRTC per encoder */
>   	i = 0;
>   	drm_for_each_encoder(encoder, dev) {
>   		if (i < max_crtc_count) {
> -			crtc = dpu_crtc_init(dev, primary_planes[i], cursor_planes[i]);
> +			crtc = dpu_crtc_init(dev, primary_planes[i], cursor_planes[i],
> +					features[encoder->index]);

A simple counter should be enough. You know the number of 'rich' CRTCs, 
which can get DSPP (or a pair of DSPPs). Then you can create a 
feature-rich CRTC provided the current encoder should use one and if the 
number of created 'rich' CRTCs is not greater than the 'possibly rich' 
number.

>   			if (IS_ERR(crtc)) {
>   				ret = PTR_ERR(crtc);
>   				return ret;
  

>-----Original Message-----
>From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>Sent: Saturday, November 12, 2022 4:13 AM
>To: Kalyan Thota (QUIC) <quic_kalyant@quicinc.com>; dri-
>devel@lists.freedesktop.org; linux-arm-msm@vger.kernel.org;
>freedreno@lists.freedesktop.org; devicetree@vger.kernel.org
>Cc: linux-kernel@vger.kernel.org; robdclark@chromium.org;
>dianders@chromium.org; swboyd@chromium.org; Vinod Polimera (QUIC)
><quic_vpolimer@quicinc.com>; Abhinav Kumar (QUIC)
><quic_abhinavk@quicinc.com>
>Subject: Re: [v1] drm/msm/disp/dpu1: add color management support for the
>crtc
>
>WARNING: This email originated from outside of Qualcomm. Please be wary of
>any links or attachments, and do not enable macros.
>
>On 11/11/2022 16:57, Kalyan Thota wrote:
>> Add color management support for the crtc provided there are enough
>> dspps that can be allocated from the catalogue.
>>
>> Changes in v1:
>> - cache color enabled state in the dpu crtc obj (Dmitry)
>> - simplify dspp allocation while creating crtc (Dmitry)
>> - register for color when crtc is created (Dmitry)
>>
>> Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
>> ---
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    |  5 +--
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h    |  6 ++--
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c |  7 ++--
>>   drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c     | 53
>++++++++++++++++++++++++++++-
>>   4 files changed, 64 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>> index 4170fbe..ca4c3b3 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>> @@ -1571,7 +1571,7 @@ static const struct drm_crtc_helper_funcs
>> dpu_crtc_helper_funcs = {
>>
>>   /* initialize crtc */
>>   struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct drm_plane
>*plane,
>> -                             struct drm_plane *cursor)
>> +                             struct drm_plane *cursor, unsigned long
>> + features)
>>   {
>>       struct drm_crtc *crtc = NULL;
>>       struct dpu_crtc *dpu_crtc = NULL; @@ -1583,6 +1583,7 @@ struct
>> drm_crtc *dpu_crtc_init(struct drm_device *dev, struct drm_plane
>> *plane,
>>
>>       crtc = &dpu_crtc->base;
>>       crtc->dev = dev;
>> +     dpu_crtc->color_enabled = features & BIT(DPU_DSPP_PCC);
>>
>>       spin_lock_init(&dpu_crtc->spin_lock);
>>       atomic_set(&dpu_crtc->frame_pending, 0); @@ -1604,7 +1605,7 @@
>> struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct
>> drm_plane *plane,
>>
>>       drm_crtc_helper_add(crtc, &dpu_crtc_helper_funcs);
>>
>> -     drm_crtc_enable_color_mgmt(crtc, 0, true, 0);
>> +     drm_crtc_enable_color_mgmt(crtc, 0, dpu_crtc->color_enabled, 0);
>>
>>       /* save user friendly CRTC name for later */
>>       snprintf(dpu_crtc->name, DPU_CRTC_NAME_SIZE, "crtc%u",
>> crtc->base.id); diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>> index 539b68b..342f9ae 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>> @@ -136,6 +136,7 @@ struct dpu_crtc_frame_event {
>>    * @enabled       : whether the DPU CRTC is currently enabled. updated in the
>>    *                  commit-thread, not state-swap time which is earlier, so
>>    *                  safe to make decisions on during VBLANK on/off work
>> + * @color_enabled : whether crtc supports color management
>>    * @feature_list  : list of color processing features supported on a crtc
>>    * @active_list   : list of color processing features are active
>>    * @dirty_list    : list of color processing features are dirty
>> @@ -164,7 +165,7 @@ struct dpu_crtc {
>>       u64 play_count;
>>       ktime_t vblank_cb_time;
>>       bool enabled;
>> -
>> +     bool color_enabled;
>>       struct list_head feature_list;
>>       struct list_head active_list;
>>       struct list_head dirty_list;
>> @@ -269,10 +270,11 @@ void dpu_crtc_complete_commit(struct drm_crtc
>*crtc);
>>    * @dev: dpu device
>>    * @plane: base plane
>>    * @cursor: cursor plane
>> + * @features: color features
>>    * @Return: new crtc object or error
>>    */
>>   struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct drm_plane
>*plane,
>> -                            struct drm_plane *cursor);
>> +                            struct drm_plane *cursor, unsigned long
>> + features);
>>
>>   /**
>>    * dpu_crtc_register_custom_event - api for enabling/disabling crtc
>> event diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> index c9058aa..d72edb8 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>> @@ -579,6 +579,7 @@ bool dpu_encoder_use_dsc_merge(struct drm_encoder
>*drm_enc)
>>   static struct msm_display_topology dpu_encoder_get_topology(
>>                       struct dpu_encoder_virt *dpu_enc,
>>                       struct dpu_kms *dpu_kms,
>> +                     struct dpu_crtc *dpu_crtc,
>>                       struct drm_display_mode *mode)
>>   {
>>       struct msm_display_topology topology = {0}; @@ -607,7 +608,7 @@
>> static struct msm_display_topology dpu_encoder_get_topology(
>>       else
>>               topology.num_lm = (mode->hdisplay > MAX_HDISPLAY_SPLIT)
>> ? 2 : 1;
>>
>> -     if (dpu_enc->disp_info.intf_type == DRM_MODE_ENCODER_DSI) {
>> +     if (dpu_crtc->color_enabled) {
>>               if (dpu_kms->catalog->dspp &&
>>                       (dpu_kms->catalog->dspp_count >= topology.num_lm))
>>                       topology.num_dspp = topology.num_lm; @@ -642,6
>> +643,7 @@ static int dpu_encoder_virt_atomic_check(
>>       struct drm_display_mode *adj_mode;
>>       struct msm_display_topology topology;
>>       struct dpu_global_state *global_state;
>> +     struct dpu_crtc *dpu_crtc;
>>       int i = 0;
>>       int ret = 0;
>>
>> @@ -652,6 +654,7 @@ static int dpu_encoder_virt_atomic_check(
>>       }
>>
>>       dpu_enc = to_dpu_encoder_virt(drm_enc);
>> +     dpu_crtc = to_dpu_crtc(crtc_state->crtc);
>>       DPU_DEBUG_ENC(dpu_enc, "\n");
>>
>>       priv = drm_enc->dev->dev_private; @@ -677,7 +680,7 @@ static int
>> dpu_encoder_virt_atomic_check(
>>               }
>>       }
>>
>> -     topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, adj_mode);
>> +     topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, dpu_crtc,
>> + adj_mode);
>>
>>       /* Reserve dynamic resources now. */
>>       if (!ret) {
>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>> index 0709da2..ce6f5e6 100644
>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>> @@ -734,7 +734,54 @@ static int _dpu_kms_setup_displays(struct drm_device
>*dev,
>>       return rc;
>>   }
>>
>> +/**
>> + * _dpu_kms_populate_dspp_features - Evaluate how many dspps pairs can be
>facilitated
>> +                                     to enable color features for encoder and assign
>> +                                  color features prefering primary
>
>preferring
>
>> + * @dpu_kms:    Pointer to dpu kms structure
>> + * @features:   Pointer to feature array
>> + *
>> + * Baring single entry, if atleast 2 dspps are available in the
>> + catalogue,
>
>at least
>
>> + * then color can be enabled for that crtc  */ static void
>> +_dpu_kms_populate_dspp_features(struct dpu_kms *dpu_kms,
>> +     unsigned long *features)
>> +{
>> +     struct drm_encoder *encoder;
>> +     u32 external_enc_mask = 0;
>> +     u32 num_dspps = dpu_kms->catalog->dspp_count;
>> +
>> +     if (!num_dspps)
>> +             return;
>> +     else if (num_dspps > 1)
>> +             num_dspps /= 2;
>> +
>> +     /* Ensure all primary encoders get first allocation of color */
>> +     drm_for_each_encoder(encoder, dpu_kms->dev) {
>> +             if(dpu_encoder_is_primary(encoder)) {
>> +                     if (num_dspps) {
>> +                             features[encoder->index] = dpu_kms->catalog->dspp-
>>features;
>> +                             num_dspps--;
>> +                     }
>> +             } else if(dpu_encoder_is_external(encoder)) {
>> +                     external_enc_mask |= drm_encoder_mask(encoder);
>> +             }
>> +     }
>> +
>> +     if(!num_dspps)
>> +             return;
>> +
>> +     /* Allocate color for external encoders after primary */
>
>Please. No "primary" encoders. You already have sense of internal vs external,
>plugable, or which ever way you would like to call them. You don't need to add
>another safety check, do you?
>
>> +     drm_for_each_encoder_mask(encoder, dpu_kms->dev,
>external_enc_mask) {
>> +             if (num_dspps) {
>> +                     features[encoder->index] = dpu_kms->catalog->dspp->features;
>> +                     num_dspps--;
>> +             }
>> +     }
>> +}
>> +
>>   #define MAX_PLANES 20
>> +#define MAX_ENCODERS 10
>>   static int _dpu_kms_drm_obj_init(struct dpu_kms *dpu_kms)
>>   {
>>       struct drm_device *dev;
>> @@ -749,6 +796,8 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms
>> *dpu_kms)
>>
>>       int primary_planes_idx = 0, cursor_planes_idx = 0, i, ret;
>>       int max_crtc_count;
>> +     unsigned long features[MAX_ENCODERS] = {0};
>> +
>>       dev = dpu_kms->dev;
>>       priv = dev->dev_private;
>>       catalog = dpu_kms->catalog;
>> @@ -798,12 +847,14 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms
>*dpu_kms)
>>       }
>>
>>       max_crtc_count = min(max_crtc_count, primary_planes_idx);
>> +     _dpu_kms_populate_dspp_features(dpu_kms, features);
>>
>>       /* Create one CRTC per encoder */
>>       i = 0;
>>       drm_for_each_encoder(encoder, dev) {
>>               if (i < max_crtc_count) {
>> -                     crtc = dpu_crtc_init(dev, primary_planes[i], cursor_planes[i]);
>> +                     crtc = dpu_crtc_init(dev, primary_planes[i], cursor_planes[i],
>> +                                     features[encoder->index]);
>
>A simple counter should be enough. You know the number of 'rich' CRTCs, which
>can get DSPP (or a pair of DSPPs). Then you can create a feature-rich CRTC
>provided the current encoder should use one and if the number of created 'rich'
>CRTCs is not greater than the 'possibly rich'
>number.
Since encoder list is iterative, and pluggable/builtin encoders can be registered in any order. we need to traverse the list 
to pick up preferred encoders so as to attach color features. I couldn't get a logic on how to accomplish that using a counter. can you explain a bit more on the idea that you have.

>
>>                       if (IS_ERR(crtc)) {
>>                               ret = PTR_ERR(crtc);
>>                               return ret;
>
>--
>With best wishes
>Dmitry
  

On 16/11/2022 17:29, Kalyan Thota wrote:
> 
> 
>> -----Original Message-----
>> From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>> Sent: Saturday, November 12, 2022 4:13 AM
>> To: Kalyan Thota (QUIC) <quic_kalyant@quicinc.com>; dri-
>> devel@lists.freedesktop.org; linux-arm-msm@vger.kernel.org;
>> freedreno@lists.freedesktop.org; devicetree@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org; robdclark@chromium.org;
>> dianders@chromium.org; swboyd@chromium.org; Vinod Polimera (QUIC)
>> <quic_vpolimer@quicinc.com>; Abhinav Kumar (QUIC)
>> <quic_abhinavk@quicinc.com>
>> Subject: Re: [v1] drm/msm/disp/dpu1: add color management support for the
>> crtc
>>
>> WARNING: This email originated from outside of Qualcomm. Please be wary of
>> any links or attachments, and do not enable macros.
>>
>> On 11/11/2022 16:57, Kalyan Thota wrote:
>>> Add color management support for the crtc provided there are enough
>>> dspps that can be allocated from the catalogue.
>>>
>>> Changes in v1:
>>> - cache color enabled state in the dpu crtc obj (Dmitry)
>>> - simplify dspp allocation while creating crtc (Dmitry)
>>> - register for color when crtc is created (Dmitry)
>>>
>>> Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
>>> ---
>>>    drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    |  5 +--
>>>    drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h    |  6 ++--
>>>    drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c |  7 ++--
>>>    drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c     | 53
>> ++++++++++++++++++++++++++++-
>>>    4 files changed, 64 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>>> index 4170fbe..ca4c3b3 100644
>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>>> @@ -1571,7 +1571,7 @@ static const struct drm_crtc_helper_funcs
>>> dpu_crtc_helper_funcs = {
>>>
>>>    /* initialize crtc */
>>>    struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct drm_plane
>> *plane,
>>> -                             struct drm_plane *cursor)
>>> +                             struct drm_plane *cursor, unsigned long
>>> + features)
>>>    {
>>>        struct drm_crtc *crtc = NULL;
>>>        struct dpu_crtc *dpu_crtc = NULL; @@ -1583,6 +1583,7 @@ struct
>>> drm_crtc *dpu_crtc_init(struct drm_device *dev, struct drm_plane
>>> *plane,
>>>
>>>        crtc = &dpu_crtc->base;
>>>        crtc->dev = dev;
>>> +     dpu_crtc->color_enabled = features & BIT(DPU_DSPP_PCC);
>>>
>>>        spin_lock_init(&dpu_crtc->spin_lock);
>>>        atomic_set(&dpu_crtc->frame_pending, 0); @@ -1604,7 +1605,7 @@
>>> struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct
>>> drm_plane *plane,
>>>
>>>        drm_crtc_helper_add(crtc, &dpu_crtc_helper_funcs);
>>>
>>> -     drm_crtc_enable_color_mgmt(crtc, 0, true, 0);
>>> +     drm_crtc_enable_color_mgmt(crtc, 0, dpu_crtc->color_enabled, 0);
>>>
>>>        /* save user friendly CRTC name for later */
>>>        snprintf(dpu_crtc->name, DPU_CRTC_NAME_SIZE, "crtc%u",
>>> crtc->base.id); diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>>> index 539b68b..342f9ae 100644
>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>>> @@ -136,6 +136,7 @@ struct dpu_crtc_frame_event {
>>>     * @enabled       : whether the DPU CRTC is currently enabled. updated in the
>>>     *                  commit-thread, not state-swap time which is earlier, so
>>>     *                  safe to make decisions on during VBLANK on/off work
>>> + * @color_enabled : whether crtc supports color management
>>>     * @feature_list  : list of color processing features supported on a crtc
>>>     * @active_list   : list of color processing features are active
>>>     * @dirty_list    : list of color processing features are dirty
>>> @@ -164,7 +165,7 @@ struct dpu_crtc {
>>>        u64 play_count;
>>>        ktime_t vblank_cb_time;
>>>        bool enabled;
>>> -
>>> +     bool color_enabled;
>>>        struct list_head feature_list;
>>>        struct list_head active_list;
>>>        struct list_head dirty_list;
>>> @@ -269,10 +270,11 @@ void dpu_crtc_complete_commit(struct drm_crtc
>> *crtc);
>>>     * @dev: dpu device
>>>     * @plane: base plane
>>>     * @cursor: cursor plane
>>> + * @features: color features
>>>     * @Return: new crtc object or error
>>>     */
>>>    struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct drm_plane
>> *plane,
>>> -                            struct drm_plane *cursor);
>>> +                            struct drm_plane *cursor, unsigned long
>>> + features);
>>>
>>>    /**
>>>     * dpu_crtc_register_custom_event - api for enabling/disabling crtc
>>> event diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>>> index c9058aa..d72edb8 100644
>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>>> @@ -579,6 +579,7 @@ bool dpu_encoder_use_dsc_merge(struct drm_encoder
>> *drm_enc)
>>>    static struct msm_display_topology dpu_encoder_get_topology(
>>>                        struct dpu_encoder_virt *dpu_enc,
>>>                        struct dpu_kms *dpu_kms,
>>> +                     struct dpu_crtc *dpu_crtc,
>>>                        struct drm_display_mode *mode)
>>>    {
>>>        struct msm_display_topology topology = {0}; @@ -607,7 +608,7 @@
>>> static struct msm_display_topology dpu_encoder_get_topology(
>>>        else
>>>                topology.num_lm = (mode->hdisplay > MAX_HDISPLAY_SPLIT)
>>> ? 2 : 1;
>>>
>>> -     if (dpu_enc->disp_info.intf_type == DRM_MODE_ENCODER_DSI) {
>>> +     if (dpu_crtc->color_enabled) {
>>>                if (dpu_kms->catalog->dspp &&
>>>                        (dpu_kms->catalog->dspp_count >= topology.num_lm))
>>>                        topology.num_dspp = topology.num_lm; @@ -642,6
>>> +643,7 @@ static int dpu_encoder_virt_atomic_check(
>>>        struct drm_display_mode *adj_mode;
>>>        struct msm_display_topology topology;
>>>        struct dpu_global_state *global_state;
>>> +     struct dpu_crtc *dpu_crtc;
>>>        int i = 0;
>>>        int ret = 0;
>>>
>>> @@ -652,6 +654,7 @@ static int dpu_encoder_virt_atomic_check(
>>>        }
>>>
>>>        dpu_enc = to_dpu_encoder_virt(drm_enc);
>>> +     dpu_crtc = to_dpu_crtc(crtc_state->crtc);
>>>        DPU_DEBUG_ENC(dpu_enc, "\n");
>>>
>>>        priv = drm_enc->dev->dev_private; @@ -677,7 +680,7 @@ static int
>>> dpu_encoder_virt_atomic_check(
>>>                }
>>>        }
>>>
>>> -     topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, adj_mode);
>>> +     topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, dpu_crtc,
>>> + adj_mode);
>>>
>>>        /* Reserve dynamic resources now. */
>>>        if (!ret) {
>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>>> index 0709da2..ce6f5e6 100644
>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>>> @@ -734,7 +734,54 @@ static int _dpu_kms_setup_displays(struct drm_device
>> *dev,
>>>        return rc;
>>>    }
>>>
>>> +/**
>>> + * _dpu_kms_populate_dspp_features - Evaluate how many dspps pairs can be
>> facilitated
>>> +                                     to enable color features for encoder and assign
>>> +                                  color features prefering primary
>>
>> preferring
>>
>>> + * @dpu_kms:    Pointer to dpu kms structure
>>> + * @features:   Pointer to feature array
>>> + *
>>> + * Baring single entry, if atleast 2 dspps are available in the
>>> + catalogue,
>>
>> at least
>>
>>> + * then color can be enabled for that crtc  */ static void
>>> +_dpu_kms_populate_dspp_features(struct dpu_kms *dpu_kms,
>>> +     unsigned long *features)
>>> +{
>>> +     struct drm_encoder *encoder;
>>> +     u32 external_enc_mask = 0;
>>> +     u32 num_dspps = dpu_kms->catalog->dspp_count;
>>> +
>>> +     if (!num_dspps)
>>> +             return;
>>> +     else if (num_dspps > 1)
>>> +             num_dspps /= 2;
>>> +
>>> +     /* Ensure all primary encoders get first allocation of color */
>>> +     drm_for_each_encoder(encoder, dpu_kms->dev) {
>>> +             if(dpu_encoder_is_primary(encoder)) {
>>> +                     if (num_dspps) {
>>> +                             features[encoder->index] = dpu_kms->catalog->dspp-
>>> features;
>>> +                             num_dspps--;
>>> +                     }
>>> +             } else if(dpu_encoder_is_external(encoder)) {
>>> +                     external_enc_mask |= drm_encoder_mask(encoder);
>>> +             }
>>> +     }
>>> +
>>> +     if(!num_dspps)
>>> +             return;
>>> +
>>> +     /* Allocate color for external encoders after primary */
>>
>> Please. No "primary" encoders. You already have sense of internal vs external,
>> plugable, or which ever way you would like to call them. You don't need to add
>> another safety check, do you?
>>
>>> +     drm_for_each_encoder_mask(encoder, dpu_kms->dev,
>> external_enc_mask) {
>>> +             if (num_dspps) {
>>> +                     features[encoder->index] = dpu_kms->catalog->dspp->features;
>>> +                     num_dspps--;
>>> +             }
>>> +     }
>>> +}
>>> +
>>>    #define MAX_PLANES 20
>>> +#define MAX_ENCODERS 10
>>>    static int _dpu_kms_drm_obj_init(struct dpu_kms *dpu_kms)
>>>    {
>>>        struct drm_device *dev;
>>> @@ -749,6 +796,8 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms
>>> *dpu_kms)
>>>
>>>        int primary_planes_idx = 0, cursor_planes_idx = 0, i, ret;
>>>        int max_crtc_count;
>>> +     unsigned long features[MAX_ENCODERS] = {0};
>>> +
>>>        dev = dpu_kms->dev;
>>>        priv = dev->dev_private;
>>>        catalog = dpu_kms->catalog;
>>> @@ -798,12 +847,14 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms
>> *dpu_kms)
>>>        }
>>>
>>>        max_crtc_count = min(max_crtc_count, primary_planes_idx);
>>> +     _dpu_kms_populate_dspp_features(dpu_kms, features);
>>>
>>>        /* Create one CRTC per encoder */
>>>        i = 0;
>>>        drm_for_each_encoder(encoder, dev) {
>>>                if (i < max_crtc_count) {
>>> -                     crtc = dpu_crtc_init(dev, primary_planes[i], cursor_planes[i]);
>>> +                     crtc = dpu_crtc_init(dev, primary_planes[i], cursor_planes[i],
>>> +                                     features[encoder->index]);
>>
>> A simple counter should be enough. You know the number of 'rich' CRTCs, which
>> can get DSPP (or a pair of DSPPs). Then you can create a feature-rich CRTC
>> provided the current encoder should use one and if the number of created 'rich'
>> CRTCs is not greater than the 'possibly rich'
>> number.
> Since encoder list is iterative, and pluggable/builtin encoders can be registered in any order. we need to traverse the list
> to pick up preferred encoders so as to attach color features. I couldn't get a logic on how to accomplish that using a counter. can you explain a bit more on the idea that you have.

drm_for_each_encoder(encoder, dev) {
   bool use_ctm = false;
   if (dpu_encoder_is_builtin(encoder, state))
     use_ctm = true;

   crtc = dpu_crtc_init(dev, primary_planes[i], cursor_planes[i], use_ctm);
}

> 
>>
>>>                        if (IS_ERR(crtc)) {
>>>                                ret = PTR_ERR(crtc);
>>>                                return ret;
>>
>> --
>> With best wishes
>> Dmitry
>
  

>-----Original Message-----
>From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>Sent: Wednesday, November 16, 2022 8:37 PM
>To: Kalyan Thota <kalyant@qti.qualcomm.com>; Kalyan Thota (QUIC)
><quic_kalyant@quicinc.com>; dri-devel@lists.freedesktop.org; linux-arm-
>msm@vger.kernel.org; freedreno@lists.freedesktop.org;
>devicetree@vger.kernel.org
>Cc: linux-kernel@vger.kernel.org; robdclark@chromium.org;
>dianders@chromium.org; swboyd@chromium.org; Vinod Polimera (QUIC)
><quic_vpolimer@quicinc.com>; Abhinav Kumar (QUIC)
><quic_abhinavk@quicinc.com>
>Subject: Re: [v1] drm/msm/disp/dpu1: add color management support for the
>crtc
>
>WARNING: This email originated from outside of Qualcomm. Please be wary of
>any links or attachments, and do not enable macros.
>
>On 16/11/2022 17:29, Kalyan Thota wrote:
>>
>>
>>> -----Original Message-----
>>> From: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
>>> Sent: Saturday, November 12, 2022 4:13 AM
>>> To: Kalyan Thota (QUIC) <quic_kalyant@quicinc.com>; dri-
>>> devel@lists.freedesktop.org; linux-arm-msm@vger.kernel.org;
>>> freedreno@lists.freedesktop.org; devicetree@vger.kernel.org
>>> Cc: linux-kernel@vger.kernel.org; robdclark@chromium.org;
>>> dianders@chromium.org; swboyd@chromium.org; Vinod Polimera (QUIC)
>>> <quic_vpolimer@quicinc.com>; Abhinav Kumar (QUIC)
>>> <quic_abhinavk@quicinc.com>
>>> Subject: Re: [v1] drm/msm/disp/dpu1: add color management support for
>>> the crtc
>>>
>>> WARNING: This email originated from outside of Qualcomm. Please be
>>> wary of any links or attachments, and do not enable macros.
>>>
>>> On 11/11/2022 16:57, Kalyan Thota wrote:
>>>> Add color management support for the crtc provided there are enough
>>>> dspps that can be allocated from the catalogue.
>>>>
>>>> Changes in v1:
>>>> - cache color enabled state in the dpu crtc obj (Dmitry)
>>>> - simplify dspp allocation while creating crtc (Dmitry)
>>>> - register for color when crtc is created (Dmitry)
>>>>
>>>> Signed-off-by: Kalyan Thota <quic_kalyant@quicinc.com>
>>>> ---
>>>>    drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c    |  5 +--
>>>>    drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h    |  6 ++--
>>>>    drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c |  7 ++--
>>>>    drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c     | 53
>>> ++++++++++++++++++++++++++++-
>>>>    4 files changed, 64 insertions(+), 7 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>>>> index 4170fbe..ca4c3b3 100644
>>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c
>>>> @@ -1571,7 +1571,7 @@ static const struct drm_crtc_helper_funcs
>>>> dpu_crtc_helper_funcs = {
>>>>
>>>>    /* initialize crtc */
>>>>    struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct
>>>> drm_plane
>>> *plane,
>>>> -                             struct drm_plane *cursor)
>>>> +                             struct drm_plane *cursor, unsigned
>>>> + long
>>>> + features)
>>>>    {
>>>>        struct drm_crtc *crtc = NULL;
>>>>        struct dpu_crtc *dpu_crtc = NULL; @@ -1583,6 +1583,7 @@
>>>> struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct
>>>> drm_plane *plane,
>>>>
>>>>        crtc = &dpu_crtc->base;
>>>>        crtc->dev = dev;
>>>> +     dpu_crtc->color_enabled = features & BIT(DPU_DSPP_PCC);
>>>>
>>>>        spin_lock_init(&dpu_crtc->spin_lock);
>>>>        atomic_set(&dpu_crtc->frame_pending, 0); @@ -1604,7 +1605,7
>>>> @@ struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct
>>>> drm_plane *plane,
>>>>
>>>>        drm_crtc_helper_add(crtc, &dpu_crtc_helper_funcs);
>>>>
>>>> -     drm_crtc_enable_color_mgmt(crtc, 0, true, 0);
>>>> +     drm_crtc_enable_color_mgmt(crtc, 0, dpu_crtc->color_enabled,
>>>> + 0);
>>>>
>>>>        /* save user friendly CRTC name for later */
>>>>        snprintf(dpu_crtc->name, DPU_CRTC_NAME_SIZE, "crtc%u",
>>>> crtc->base.id); diff --git
>>>> crtc->a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>>>> index 539b68b..342f9ae 100644
>>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.h
>>>> @@ -136,6 +136,7 @@ struct dpu_crtc_frame_event {
>>>>     * @enabled       : whether the DPU CRTC is currently enabled. updated in
>the
>>>>     *                  commit-thread, not state-swap time which is earlier, so
>>>>     *                  safe to make decisions on during VBLANK on/off work
>>>> + * @color_enabled : whether crtc supports color management
>>>>     * @feature_list  : list of color processing features supported on a crtc
>>>>     * @active_list   : list of color processing features are active
>>>>     * @dirty_list    : list of color processing features are dirty
>>>> @@ -164,7 +165,7 @@ struct dpu_crtc {
>>>>        u64 play_count;
>>>>        ktime_t vblank_cb_time;
>>>>        bool enabled;
>>>> -
>>>> +     bool color_enabled;
>>>>        struct list_head feature_list;
>>>>        struct list_head active_list;
>>>>        struct list_head dirty_list;
>>>> @@ -269,10 +270,11 @@ void dpu_crtc_complete_commit(struct drm_crtc
>>> *crtc);
>>>>     * @dev: dpu device
>>>>     * @plane: base plane
>>>>     * @cursor: cursor plane
>>>> + * @features: color features
>>>>     * @Return: new crtc object or error
>>>>     */
>>>>    struct drm_crtc *dpu_crtc_init(struct drm_device *dev, struct
>>>> drm_plane
>>> *plane,
>>>> -                            struct drm_plane *cursor);
>>>> +                            struct drm_plane *cursor, unsigned long
>>>> + features);
>>>>
>>>>    /**
>>>>     * dpu_crtc_register_custom_event - api for enabling/disabling
>>>> crtc event diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>>>> index c9058aa..d72edb8 100644
>>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
>>>> @@ -579,6 +579,7 @@ bool dpu_encoder_use_dsc_merge(struct
>>>> drm_encoder
>>> *drm_enc)
>>>>    static struct msm_display_topology dpu_encoder_get_topology(
>>>>                        struct dpu_encoder_virt *dpu_enc,
>>>>                        struct dpu_kms *dpu_kms,
>>>> +                     struct dpu_crtc *dpu_crtc,
>>>>                        struct drm_display_mode *mode)
>>>>    {
>>>>        struct msm_display_topology topology = {0}; @@ -607,7 +608,7
>>>> @@ static struct msm_display_topology dpu_encoder_get_topology(
>>>>        else
>>>>                topology.num_lm = (mode->hdisplay >
>>>> MAX_HDISPLAY_SPLIT) ? 2 : 1;
>>>>
>>>> -     if (dpu_enc->disp_info.intf_type == DRM_MODE_ENCODER_DSI) {
>>>> +     if (dpu_crtc->color_enabled) {
>>>>                if (dpu_kms->catalog->dspp &&
>>>>                        (dpu_kms->catalog->dspp_count >= topology.num_lm))
>>>>                        topology.num_dspp = topology.num_lm; @@
>>>> -642,6
>>>> +643,7 @@ static int dpu_encoder_virt_atomic_check(
>>>>        struct drm_display_mode *adj_mode;
>>>>        struct msm_display_topology topology;
>>>>        struct dpu_global_state *global_state;
>>>> +     struct dpu_crtc *dpu_crtc;
>>>>        int i = 0;
>>>>        int ret = 0;
>>>>
>>>> @@ -652,6 +654,7 @@ static int dpu_encoder_virt_atomic_check(
>>>>        }
>>>>
>>>>        dpu_enc = to_dpu_encoder_virt(drm_enc);
>>>> +     dpu_crtc = to_dpu_crtc(crtc_state->crtc);
>>>>        DPU_DEBUG_ENC(dpu_enc, "\n");
>>>>
>>>>        priv = drm_enc->dev->dev_private; @@ -677,7 +680,7 @@ static
>>>> int dpu_encoder_virt_atomic_check(
>>>>                }
>>>>        }
>>>>
>>>> -     topology = dpu_encoder_get_topology(dpu_enc, dpu_kms, adj_mode);
>>>> +     topology = dpu_encoder_get_topology(dpu_enc, dpu_kms,
>>>> + dpu_crtc, adj_mode);
>>>>
>>>>        /* Reserve dynamic resources now. */
>>>>        if (!ret) {
>>>> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>>>> b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>>>> index 0709da2..ce6f5e6 100644
>>>> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>>>> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c
>>>> @@ -734,7 +734,54 @@ static int _dpu_kms_setup_displays(struct
>>>> drm_device
>>> *dev,
>>>>        return rc;
>>>>    }
>>>>
>>>> +/**
>>>> + * _dpu_kms_populate_dspp_features - Evaluate how many dspps pairs
>>>> +can be
>>> facilitated
>>>> +                                     to enable color features for encoder and assign
>>>> +                                  color features prefering primary
>>>
>>> preferring
>>>
>>>> + * @dpu_kms:    Pointer to dpu kms structure
>>>> + * @features:   Pointer to feature array
>>>> + *
>>>> + * Baring single entry, if atleast 2 dspps are available in the
>>>> + catalogue,
>>>
>>> at least
>>>
>>>> + * then color can be enabled for that crtc  */ static void
>>>> +_dpu_kms_populate_dspp_features(struct dpu_kms *dpu_kms,
>>>> +     unsigned long *features)
>>>> +{
>>>> +     struct drm_encoder *encoder;
>>>> +     u32 external_enc_mask = 0;
>>>> +     u32 num_dspps = dpu_kms->catalog->dspp_count;
>>>> +
>>>> +     if (!num_dspps)
>>>> +             return;
>>>> +     else if (num_dspps > 1)
>>>> +             num_dspps /= 2;
>>>> +
>>>> +     /* Ensure all primary encoders get first allocation of color */
>>>> +     drm_for_each_encoder(encoder, dpu_kms->dev) {
>>>> +             if(dpu_encoder_is_primary(encoder)) {
>>>> +                     if (num_dspps) {
>>>> +                             features[encoder->index] =
>>>> + dpu_kms->catalog->dspp-
>>>> features;
>>>> +                             num_dspps--;
>>>> +                     }
>>>> +             } else if(dpu_encoder_is_external(encoder)) {
>>>> +                     external_enc_mask |= drm_encoder_mask(encoder);
>>>> +             }
>>>> +     }
>>>> +
>>>> +     if(!num_dspps)
>>>> +             return;
>>>> +
>>>> +     /* Allocate color for external encoders after primary */
>>>
>>> Please. No "primary" encoders. You already have sense of internal vs
>>> external, plugable, or which ever way you would like to call them.
>>> You don't need to add another safety check, do you?
>>>
>>>> +     drm_for_each_encoder_mask(encoder, dpu_kms->dev,
>>> external_enc_mask) {
>>>> +             if (num_dspps) {
>>>> +                     features[encoder->index] = dpu_kms->catalog->dspp->features;
>>>> +                     num_dspps--;
>>>> +             }
>>>> +     }
>>>> +}
>>>> +
>>>>    #define MAX_PLANES 20
>>>> +#define MAX_ENCODERS 10
>>>>    static int _dpu_kms_drm_obj_init(struct dpu_kms *dpu_kms)
>>>>    {
>>>>        struct drm_device *dev;
>>>> @@ -749,6 +796,8 @@ static int _dpu_kms_drm_obj_init(struct dpu_kms
>>>> *dpu_kms)
>>>>
>>>>        int primary_planes_idx = 0, cursor_planes_idx = 0, i, ret;
>>>>        int max_crtc_count;
>>>> +     unsigned long features[MAX_ENCODERS] = {0};
>>>> +
>>>>        dev = dpu_kms->dev;
>>>>        priv = dev->dev_private;
>>>>        catalog = dpu_kms->catalog;
>>>> @@ -798,12 +847,14 @@ static int _dpu_kms_drm_obj_init(struct
>>>> dpu_kms
>>> *dpu_kms)
>>>>        }
>>>>
>>>>        max_crtc_count = min(max_crtc_count, primary_planes_idx);
>>>> +     _dpu_kms_populate_dspp_features(dpu_kms, features);
>>>>
>>>>        /* Create one CRTC per encoder */
>>>>        i = 0;
>>>>        drm_for_each_encoder(encoder, dev) {
>>>>                if (i < max_crtc_count) {
>>>> -                     crtc = dpu_crtc_init(dev, primary_planes[i], cursor_planes[i]);
>>>> +                     crtc = dpu_crtc_init(dev, primary_planes[i], cursor_planes[i],
>>>> +                                     features[encoder->index]);
>>>
>>> A simple counter should be enough. You know the number of 'rich'
>>> CRTCs, which can get DSPP (or a pair of DSPPs). Then you can create a
>>> feature-rich CRTC provided the current encoder should use one and if the
>number of created 'rich'
>>> CRTCs is not greater than the 'possibly rich'
>>> number.
>> Since encoder list is iterative, and pluggable/builtin encoders can be
>> registered in any order. we need to traverse the list to pick up preferred
>encoders so as to attach color features. I couldn't get a logic on how to
>accomplish that using a counter. can you explain a bit more on the idea that you
>have.
>
>drm_for_each_encoder(encoder, dev) {
>   bool use_ctm = false;
>   if (dpu_encoder_is_builtin(encoder, state))
>     use_ctm = true;
>
>   crtc = dpu_crtc_init(dev, primary_planes[i], cursor_planes[i], use_ctm); }
>
For Example:
If encoders registered in the list are as follows and you have 2 crtcs that can enable color
Enc_list: DP, WB, eDP
Shouldn't we determine first on how many are eligible and then assign the feature based on preference ? 
I am thinking as, eDP should get first and others should also be considered after eDP if resources are available
But as list is iterative, we already passed though DP. 

Let me know your thoughts

>>
>>>
>>>>                        if (IS_ERR(crtc)) {
>>>>                                ret = PTR_ERR(crtc);
>>>>                                return ret;
>>>
>>> --
>>> With best wishes
>>> Dmitry
>>
>
>--
>With best wishes
>Dmitry