[3/4,v5] drm/i915/color: Extract icl_read_luts()
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Message ID 20191009065542.27415-4-swati2.sharma@intel.com
State New
Headers show
Series
  • fix broken state checker and enable state checker for icl+
Related show

Commit Message

Swati Sharma Oct. 9, 2019, 6:55 a.m. UTC
For icl+, have hw read out to create hw blob of gamma
lut values. icl+ platforms supports multi segmented gamma
mode by default, add hw lut creation for this mode.

This will be used to validate gamma programming using dsb
(display state buffer) which is a tgl specific feature.

Major change done-removal of readouts of coarse and fine segments
because PAL_PREC_DATA register isn't giving propoer values.
State checker limited only to "fine segment"

v2: -readout code for multisegmented gamma has to come
     up with some intermediate entries that aren't preserved
     in hardware (Jani N)
    -linear interpolation (Ville)
    -moved common code to check gamma_enable to specific funcs,
     since icl doesn't support that
v3: -use u16 instead of __u16 [Jani N]
    -used single lut [Jani N]
    -improved and more readable for loops [Jani N]
    -read values directly to actual locations and then fill gaps [Jani N]
    -moved cleaning to patch 1 [Jani N]
    -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
     make it similar to icl_load_luts()
    -renamed icl_compute_interpolated_gamma_blob() to
     icl_compute_interpolated_gamma_lut_values() more sensible, I guess
v4: -removed interpolated func for creating gamma lut values
    -removed readouts of fine and coarse segments, failure to read PAL_PREC_DATA
     correctly
v5: -added gamma_enable check inside read_luts()

Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
---
 drivers/gpu/drm/i915/display/intel_color.c | 114 ++++++++++++++++++---
 drivers/gpu/drm/i915/i915_reg.h            |   6 ++
 2 files changed, 108 insertions(+), 12 deletions(-)

Comments

Ville Syrjälä Oct. 9, 2019, 2:16 p.m. UTC | #1
On Wed, Oct 09, 2019 at 12:25:41PM +0530, Swati Sharma wrote:
> For icl+, have hw read out to create hw blob of gamma
> lut values. icl+ platforms supports multi segmented gamma
> mode by default, add hw lut creation for this mode.
> 
> This will be used to validate gamma programming using dsb
> (display state buffer) which is a tgl specific feature.
> 
> Major change done-removal of readouts of coarse and fine segments
> because PAL_PREC_DATA register isn't giving propoer values.
> State checker limited only to "fine segment"
> 
> v2: -readout code for multisegmented gamma has to come
>      up with some intermediate entries that aren't preserved
>      in hardware (Jani N)
>     -linear interpolation (Ville)
>     -moved common code to check gamma_enable to specific funcs,
>      since icl doesn't support that
> v3: -use u16 instead of __u16 [Jani N]
>     -used single lut [Jani N]
>     -improved and more readable for loops [Jani N]
>     -read values directly to actual locations and then fill gaps [Jani N]
>     -moved cleaning to patch 1 [Jani N]
>     -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
>      make it similar to icl_load_luts()
>     -renamed icl_compute_interpolated_gamma_blob() to
>      icl_compute_interpolated_gamma_lut_values() more sensible, I guess
> v4: -removed interpolated func for creating gamma lut values
>     -removed readouts of fine and coarse segments, failure to read PAL_PREC_DATA
>      correctly
> v5: -added gamma_enable check inside read_luts()
> 
> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_color.c | 114 ++++++++++++++++++---
>  drivers/gpu/drm/i915/i915_reg.h            |   6 ++
>  2 files changed, 108 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
> index fa44eb73d088..614e0ad386ca 100644
> --- a/drivers/gpu/drm/i915/display/intel_color.c
> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> @@ -1477,6 +1477,25 @@ static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
>  	}
>  }
>  
> +static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
> +{
> +	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
> +		return 0;
> +
> +	switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
> +	case GAMMA_MODE_MODE_8BIT:
> +		return 8;
> +	case GAMMA_MODE_MODE_10BIT:
> +		return 10;
> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> +		return 16;
> +	default:
> +		MISSING_CASE(crtc_state->gamma_mode);
> +		return 0;
> +	}
> +
> +}
> +
>  int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
>  {
>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
> @@ -1488,7 +1507,9 @@ int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_stat
>  		else
>  			return i9xx_gamma_precision(crtc_state);
>  	} else {
> -		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
> +		if (INTEL_GEN(dev_priv) >= 11)
> +			return icl_gamma_precision(crtc_state);
> +		else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
>  			return glk_gamma_precision(crtc_state);
>  		else if (IS_IRONLAKE(dev_priv))
>  			return ilk_gamma_precision(crtc_state);
> @@ -1519,6 +1540,20 @@ static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
>  	return true;
>  }
>  
> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
> +					      struct drm_color_lut *lut2,
> +					      int lut_size, u32 err)
> +{
> +	int i;
> +
> +	for (i = 0; i < 9; i++) {
> +		if (!err_check(&lut1[i], &lut2[i], err))
> +			return false;
> +	}
> +
> +	return true;
> +}
> +
>  bool intel_color_lut_equal(struct drm_property_blob *blob1,
>  			   struct drm_property_blob *blob2,
>  			   u32 gamma_mode, u32 bit_precision)
> @@ -1537,16 +1572,8 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>  	lut_size2 = drm_color_lut_size(blob2);
>  
>  	/* check sw and hw lut size */
> -	switch (gamma_mode) {
> -	case GAMMA_MODE_MODE_8BIT:
> -	case GAMMA_MODE_MODE_10BIT:
> -		if (lut_size1 != lut_size2)
> -			return false;
> -		break;
> -	default:
> -		MISSING_CASE(gamma_mode);
> -			return false;
> -	}
> +	if (lut_size1 != lut_size2)
> +		return false;
>  
>  	lut1 = blob1->data;
>  	lut2 = blob2->data;
> @@ -1554,13 +1581,18 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>  	err = 0xffff >> bit_precision;
>  
>  	/* check sw and hw lut entry to be equal */
> -	switch (gamma_mode) {
> +	switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
>  	case GAMMA_MODE_MODE_8BIT:
>  	case GAMMA_MODE_MODE_10BIT:
>  		if (!intel_color_lut_entry_equal(lut1, lut2,
>  						 lut_size2, err))
>  			return false;
>  		break;
> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> +		if (!intel_color_lut_entry_multi_equal(lut1, lut2,
> +						       lut_size2, err))

I don't think you need a new function for that. Just pass 9 as the size
to intel_color_lut_entry_equal() ?

Hmm, should probably rename that to just intel_color_lut_equal() since
it checks the entire LUT (or at least the specified subset) and not
just a single entry...

> +			return false;
> +		break;
>  	default:
>  		MISSING_CASE(gamma_mode);
>  			return false;
> @@ -1815,6 +1847,63 @@ static void glk_read_luts(struct intel_crtc_state *crtc_state)
>  		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
>  }
>  
> +static struct drm_property_blob *
> +icl_read_lut_multi_segment(const struct intel_crtc_state *crtc_state)
> +{
> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
> +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> +	int lut_size = INTEL_INFO(dev_priv)->color.gamma_lut_size;
> +	enum pipe pipe = crtc->pipe;
> +	struct drm_property_blob *blob;
> +	struct drm_color_lut *blob_data;
> +	u32 i, val1, val2;
> +
> +	blob = drm_property_create_blob(&dev_priv->drm,
> +					sizeof(struct drm_color_lut) * lut_size,
> +					NULL);
> +	if (IS_ERR(blob))
> +		return NULL;
> +
> +	blob_data = blob->data;
> +
> +	I915_WRITE(PREC_PAL_MULTI_SEG_INDEX(pipe), PAL_PREC_AUTO_INCREMENT);
> +
> +	for (i = 0; i < 9; i++) {
> +		val1 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
> +		val2 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
> +
> +		blob_data[i].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
> +				   REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
> +		blob_data[i].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
> +				     REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
> +		blob_data[i].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
> +				    REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
> +	}
> +
> +	/*
> +	 * FIXME readouts from PAL_PREC_DATA register aren't giving correct values
> +	 * in the case of fine and coarse segments. Restricting readouts only for
> +	 * super fine segment as of now.
> +	 */
> +
> +	return blob;
> +}
> +
> +static void icl_read_luts(struct intel_crtc_state *crtc_state)
> +{
> +	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
> +		return;
> +
> +	if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
> +	    GAMMA_MODE_MODE_8BIT)

Please make this a switch statement.

I pushed patches 1-2 to dinq. Thanks.

> +		crtc_state->base.gamma_lut = i9xx_read_lut_8(crtc_state);
> +	else if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
> +		 GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED)
> +		crtc_state->base.gamma_lut = icl_read_lut_multi_segment(crtc_state);
> +	else
> +		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
> +}
> +
>  void intel_color_init(struct intel_crtc *crtc)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
> @@ -1858,6 +1947,7 @@ void intel_color_init(struct intel_crtc *crtc)
>  
>  		if (INTEL_GEN(dev_priv) >= 11) {
>  			dev_priv->display.load_luts = icl_load_luts;
> +			dev_priv->display.read_luts = icl_read_luts;
>  		} else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv)) {
>  			dev_priv->display.load_luts = glk_load_luts;
>  			dev_priv->display.read_luts = glk_read_luts;
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index 1dc067fc57ab..06b6398b7d62 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -10584,6 +10584,12 @@ enum skl_power_gate {
>  
>  #define _PAL_PREC_MULTI_SEG_DATA_A	0x4A40C
>  #define _PAL_PREC_MULTI_SEG_DATA_B	0x4AC0C
> +#define  PAL_PREC_MULTI_SEG_RED_LDW_MASK   REG_GENMASK(29, 24)
> +#define  PAL_PREC_MULTI_SEG_RED_UDW_MASK   REG_GENMASK(29, 20)
> +#define  PAL_PREC_MULTI_SEG_GREEN_LDW_MASK REG_GENMASK(19, 14)
> +#define  PAL_PREC_MULTI_SEG_GREEN_UDW_MASK REG_GENMASK(19, 10)
> +#define  PAL_PREC_MULTI_SEG_BLUE_LDW_MASK  REG_GENMASK(9, 4)
> +#define  PAL_PREC_MULTI_SEG_BLUE_UDW_MASK  REG_GENMASK(9, 0)
>  
>  #define PREC_PAL_MULTI_SEG_INDEX(pipe)	_MMIO_PIPE(pipe, \
>  					_PAL_PREC_MULTI_SEG_INDEX_A, \
> -- 
> 2.23.0
Swati Sharma Oct. 10, 2019, 10:50 a.m. UTC | #2
On 09-Oct-19 7:46 PM, Ville Syrjälä wrote:
> On Wed, Oct 09, 2019 at 12:25:41PM +0530, Swati Sharma wrote:
>> For icl+, have hw read out to create hw blob of gamma
>> lut values. icl+ platforms supports multi segmented gamma
>> mode by default, add hw lut creation for this mode.
>>
>> This will be used to validate gamma programming using dsb
>> (display state buffer) which is a tgl specific feature.
>>
>> Major change done-removal of readouts of coarse and fine segments
>> because PAL_PREC_DATA register isn't giving propoer values.
>> State checker limited only to "fine segment"
>>
>> v2: -readout code for multisegmented gamma has to come
>>       up with some intermediate entries that aren't preserved
>>       in hardware (Jani N)
>>      -linear interpolation (Ville)
>>      -moved common code to check gamma_enable to specific funcs,
>>       since icl doesn't support that
>> v3: -use u16 instead of __u16 [Jani N]
>>      -used single lut [Jani N]
>>      -improved and more readable for loops [Jani N]
>>      -read values directly to actual locations and then fill gaps [Jani N]
>>      -moved cleaning to patch 1 [Jani N]
>>      -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
>>       make it similar to icl_load_luts()
>>      -renamed icl_compute_interpolated_gamma_blob() to
>>       icl_compute_interpolated_gamma_lut_values() more sensible, I guess
>> v4: -removed interpolated func for creating gamma lut values
>>      -removed readouts of fine and coarse segments, failure to read PAL_PREC_DATA
>>       correctly
>> v5: -added gamma_enable check inside read_luts()
>>
>> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
>> ---
>>   drivers/gpu/drm/i915/display/intel_color.c | 114 ++++++++++++++++++---
>>   drivers/gpu/drm/i915/i915_reg.h            |   6 ++
>>   2 files changed, 108 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
>> index fa44eb73d088..614e0ad386ca 100644
>> --- a/drivers/gpu/drm/i915/display/intel_color.c
>> +++ b/drivers/gpu/drm/i915/display/intel_color.c
>> @@ -1477,6 +1477,25 @@ static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
>>   	}
>>   }
>>   
>> +static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
>> +{
>> +	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
>> +		return 0;
>> +
>> +	switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
>> +	case GAMMA_MODE_MODE_8BIT:
>> +		return 8;
>> +	case GAMMA_MODE_MODE_10BIT:
>> +		return 10;
>> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
>> +		return 16;
>> +	default:
>> +		MISSING_CASE(crtc_state->gamma_mode);
>> +		return 0;
>> +	}
>> +
>> +}
>> +
>>   int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
>>   {
>>   	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
>> @@ -1488,7 +1507,9 @@ int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_stat
>>   		else
>>   			return i9xx_gamma_precision(crtc_state);
>>   	} else {
>> -		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
>> +		if (INTEL_GEN(dev_priv) >= 11)
>> +			return icl_gamma_precision(crtc_state);
>> +		else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
>>   			return glk_gamma_precision(crtc_state);
>>   		else if (IS_IRONLAKE(dev_priv))
>>   			return ilk_gamma_precision(crtc_state);
>> @@ -1519,6 +1540,20 @@ static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
>>   	return true;
>>   }
>>   
>> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
>> +					      struct drm_color_lut *lut2,
>> +					      int lut_size, u32 err)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < 9; i++) {
>> +		if (!err_check(&lut1[i], &lut2[i], err))
>> +			return false;
>> +	}
>> +
>> +	return true;
>> +}
>> +
>>   bool intel_color_lut_equal(struct drm_property_blob *blob1,
>>   			   struct drm_property_blob *blob2,
>>   			   u32 gamma_mode, u32 bit_precision)
>> @@ -1537,16 +1572,8 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>>   	lut_size2 = drm_color_lut_size(blob2);
>>   
>>   	/* check sw and hw lut size */
>> -	switch (gamma_mode) {
>> -	case GAMMA_MODE_MODE_8BIT:
>> -	case GAMMA_MODE_MODE_10BIT:
>> -		if (lut_size1 != lut_size2)
>> -			return false;
>> -		break;
>> -	default:
>> -		MISSING_CASE(gamma_mode);
>> -			return false;
>> -	}
>> +	if (lut_size1 != lut_size2)
>> +		return false;
>>   
>>   	lut1 = blob1->data;
>>   	lut2 = blob2->data;
>> @@ -1554,13 +1581,18 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>>   	err = 0xffff >> bit_precision;
>>   
>>   	/* check sw and hw lut entry to be equal */
>> -	switch (gamma_mode) {
>> +	switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
>>   	case GAMMA_MODE_MODE_8BIT:
>>   	case GAMMA_MODE_MODE_10BIT:
>>   		if (!intel_color_lut_entry_equal(lut1, lut2,
>>   						 lut_size2, err))
>>   			return false;
>>   		break;
>> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
>> +		if (!intel_color_lut_entry_multi_equal(lut1, lut2,
>> +						       lut_size2, err))
> 
> I don't think you need a new function for that. Just pass 9 as the size
> to intel_color_lut_entry_equal() ?

I had made a separate function for multi-segmented gamma since there 
will be 3 loops for comparing superfine, fine and course segments which 
wont go with intel_lut_entry_equal() structure.

Right now we are limiting to superfine segment only but in future we 
will add for other segments too (once we get fix from h/w)

Func() should look like this. Actually there is no need to passing 
lut_size only in this function if we continue with this function only.

+static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
+                                             struct drm_color_lut *lut2,
+                                             int lut_size, u32 err)
+{
+       int i;
+
+       for (i = 0; i < 9; i++) {
+               if (!err_check(&lut1[i], &lut2[i], err))
+                       return false;
+       }
+
+       for (i = 1; i < 257; i++) {
+               if (!err_check(&lut1[i * 8], &lut2[i * 8], err))
+                       return false;
+       }
+
+       for (i = 0; i < 256; i++) {
+               if (!err_check(&lut1[i * 8 * 128], &lut2[i * 8 * 128], err))
+                       return false;
+       }
+
+       return true;
+}
+
Please suggest.

> 
> Hmm, should probably rename that to just intel_color_lut_equal() since
> it checks the entire LUT (or at least the specified subset) and not
> just a single entry...

This will be fine for this segment but for other two segments it won't 
work. Right?
> 
>> +			return false;
>> +		break;
>>   	default:
>>   		MISSING_CASE(gamma_mode);
>>   			return false;
>> @@ -1815,6 +1847,63 @@ static void glk_read_luts(struct intel_crtc_state *crtc_state)
>>   		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
>>   }
>>   
>> +static struct drm_property_blob *
>> +icl_read_lut_multi_segment(const struct intel_crtc_state *crtc_state)
>> +{
>> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
>> +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>> +	int lut_size = INTEL_INFO(dev_priv)->color.gamma_lut_size;
>> +	enum pipe pipe = crtc->pipe;
>> +	struct drm_property_blob *blob;
>> +	struct drm_color_lut *blob_data;
>> +	u32 i, val1, val2;
>> +
>> +	blob = drm_property_create_blob(&dev_priv->drm,
>> +					sizeof(struct drm_color_lut) * lut_size,
>> +					NULL);
>> +	if (IS_ERR(blob))
>> +		return NULL;
>> +
>> +	blob_data = blob->data;
>> +
>> +	I915_WRITE(PREC_PAL_MULTI_SEG_INDEX(pipe), PAL_PREC_AUTO_INCREMENT);
>> +
>> +	for (i = 0; i < 9; i++) {
>> +		val1 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
>> +		val2 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
>> +
>> +		blob_data[i].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
>> +				   REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
>> +		blob_data[i].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
>> +				     REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
>> +		blob_data[i].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
>> +				    REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
>> +	}
>> +
>> +	/*
>> +	 * FIXME readouts from PAL_PREC_DATA register aren't giving correct values
>> +	 * in the case of fine and coarse segments. Restricting readouts only for
>> +	 * super fine segment as of now.
>> +	 */
>> +
>> +	return blob;
>> +}
>> +
>> +static void icl_read_luts(struct intel_crtc_state *crtc_state)
>> +{
>> +	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
>> +		return;
>> +
>> +	if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
>> +	    GAMMA_MODE_MODE_8BIT)
> 
> Please make this a switch statement.
> 
> I pushed patches 1-2 to dinq. Thanks.
> 
>> +		crtc_state->base.gamma_lut = i9xx_read_lut_8(crtc_state);
>> +	else if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
>> +		 GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED)
>> +		crtc_state->base.gamma_lut = icl_read_lut_multi_segment(crtc_state);
>> +	else
>> +		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
>> +}
>> +
>>   void intel_color_init(struct intel_crtc *crtc)
>>   {
>>   	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>> @@ -1858,6 +1947,7 @@ void intel_color_init(struct intel_crtc *crtc)
>>   
>>   		if (INTEL_GEN(dev_priv) >= 11) {
>>   			dev_priv->display.load_luts = icl_load_luts;
>> +			dev_priv->display.read_luts = icl_read_luts;
>>   		} else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv)) {
>>   			dev_priv->display.load_luts = glk_load_luts;
>>   			dev_priv->display.read_luts = glk_read_luts;
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index 1dc067fc57ab..06b6398b7d62 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -10584,6 +10584,12 @@ enum skl_power_gate {
>>   
>>   #define _PAL_PREC_MULTI_SEG_DATA_A	0x4A40C
>>   #define _PAL_PREC_MULTI_SEG_DATA_B	0x4AC0C
>> +#define  PAL_PREC_MULTI_SEG_RED_LDW_MASK   REG_GENMASK(29, 24)
>> +#define  PAL_PREC_MULTI_SEG_RED_UDW_MASK   REG_GENMASK(29, 20)
>> +#define  PAL_PREC_MULTI_SEG_GREEN_LDW_MASK REG_GENMASK(19, 14)
>> +#define  PAL_PREC_MULTI_SEG_GREEN_UDW_MASK REG_GENMASK(19, 10)
>> +#define  PAL_PREC_MULTI_SEG_BLUE_LDW_MASK  REG_GENMASK(9, 4)
>> +#define  PAL_PREC_MULTI_SEG_BLUE_UDW_MASK  REG_GENMASK(9, 0)
>>   
>>   #define PREC_PAL_MULTI_SEG_INDEX(pipe)	_MMIO_PIPE(pipe, \
>>   					_PAL_PREC_MULTI_SEG_INDEX_A, \
>> -- 
>> 2.23.0
>
Jani Nikula Oct. 15, 2019, 7:59 a.m. UTC | #3
On Wed, 09 Oct 2019, Ville Syrjälä <ville.syrjala@linux.intel.com> wrote:
> On Wed, Oct 09, 2019 at 12:25:41PM +0530, Swati Sharma wrote:
>> For icl+, have hw read out to create hw blob of gamma
>> lut values. icl+ platforms supports multi segmented gamma
>> mode by default, add hw lut creation for this mode.
>> 
>> This will be used to validate gamma programming using dsb
>> (display state buffer) which is a tgl specific feature.
>> 
>> Major change done-removal of readouts of coarse and fine segments
>> because PAL_PREC_DATA register isn't giving propoer values.
>> State checker limited only to "fine segment"
>> 
>> v2: -readout code for multisegmented gamma has to come
>>      up with some intermediate entries that aren't preserved
>>      in hardware (Jani N)
>>     -linear interpolation (Ville)
>>     -moved common code to check gamma_enable to specific funcs,
>>      since icl doesn't support that
>> v3: -use u16 instead of __u16 [Jani N]
>>     -used single lut [Jani N]
>>     -improved and more readable for loops [Jani N]
>>     -read values directly to actual locations and then fill gaps [Jani N]
>>     -moved cleaning to patch 1 [Jani N]
>>     -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
>>      make it similar to icl_load_luts()
>>     -renamed icl_compute_interpolated_gamma_blob() to
>>      icl_compute_interpolated_gamma_lut_values() more sensible, I guess
>> v4: -removed interpolated func for creating gamma lut values
>>     -removed readouts of fine and coarse segments, failure to read PAL_PREC_DATA
>>      correctly
>> v5: -added gamma_enable check inside read_luts()
>> 
>> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_color.c | 114 ++++++++++++++++++---
>>  drivers/gpu/drm/i915/i915_reg.h            |   6 ++
>>  2 files changed, 108 insertions(+), 12 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
>> index fa44eb73d088..614e0ad386ca 100644
>> --- a/drivers/gpu/drm/i915/display/intel_color.c
>> +++ b/drivers/gpu/drm/i915/display/intel_color.c
>> @@ -1477,6 +1477,25 @@ static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
>>  	}
>>  }
>>  
>> +static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
>> +{
>> +	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
>> +		return 0;
>> +
>> +	switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
>> +	case GAMMA_MODE_MODE_8BIT:
>> +		return 8;
>> +	case GAMMA_MODE_MODE_10BIT:
>> +		return 10;
>> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
>> +		return 16;
>> +	default:
>> +		MISSING_CASE(crtc_state->gamma_mode);
>> +		return 0;
>> +	}
>> +
>> +}
>> +
>>  int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
>>  {
>>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
>> @@ -1488,7 +1507,9 @@ int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_stat
>>  		else
>>  			return i9xx_gamma_precision(crtc_state);
>>  	} else {
>> -		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
>> +		if (INTEL_GEN(dev_priv) >= 11)
>> +			return icl_gamma_precision(crtc_state);
>> +		else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
>>  			return glk_gamma_precision(crtc_state);
>>  		else if (IS_IRONLAKE(dev_priv))
>>  			return ilk_gamma_precision(crtc_state);
>> @@ -1519,6 +1540,20 @@ static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
>>  	return true;
>>  }
>>  
>> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
>> +					      struct drm_color_lut *lut2,
>> +					      int lut_size, u32 err)
>> +{
>> +	int i;
>> +
>> +	for (i = 0; i < 9; i++) {
>> +		if (!err_check(&lut1[i], &lut2[i], err))
>> +			return false;
>> +	}
>> +
>> +	return true;
>> +}
>> +
>>  bool intel_color_lut_equal(struct drm_property_blob *blob1,
>>  			   struct drm_property_blob *blob2,
>>  			   u32 gamma_mode, u32 bit_precision)
>> @@ -1537,16 +1572,8 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>>  	lut_size2 = drm_color_lut_size(blob2);
>>  
>>  	/* check sw and hw lut size */
>> -	switch (gamma_mode) {
>> -	case GAMMA_MODE_MODE_8BIT:
>> -	case GAMMA_MODE_MODE_10BIT:
>> -		if (lut_size1 != lut_size2)
>> -			return false;
>> -		break;
>> -	default:
>> -		MISSING_CASE(gamma_mode);
>> -			return false;
>> -	}
>> +	if (lut_size1 != lut_size2)
>> +		return false;
>>  
>>  	lut1 = blob1->data;
>>  	lut2 = blob2->data;
>> @@ -1554,13 +1581,18 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>>  	err = 0xffff >> bit_precision;
>>  
>>  	/* check sw and hw lut entry to be equal */
>> -	switch (gamma_mode) {
>> +	switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
>>  	case GAMMA_MODE_MODE_8BIT:
>>  	case GAMMA_MODE_MODE_10BIT:
>>  		if (!intel_color_lut_entry_equal(lut1, lut2,
>>  						 lut_size2, err))
>>  			return false;
>>  		break;
>> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
>> +		if (!intel_color_lut_entry_multi_equal(lut1, lut2,
>> +						       lut_size2, err))
>
> I don't think you need a new function for that. Just pass 9 as the size
> to intel_color_lut_entry_equal() ?

I think the idea is to prepare for if/when we can actually check the
multi-segmented case where we have items that need to be ignored with
different spacing.

BR,
Jani.


>
> Hmm, should probably rename that to just intel_color_lut_equal() since
> it checks the entire LUT (or at least the specified subset) and not
> just a single entry...
>
>> +			return false;
>> +		break;
>>  	default:
>>  		MISSING_CASE(gamma_mode);
>>  			return false;
>> @@ -1815,6 +1847,63 @@ static void glk_read_luts(struct intel_crtc_state *crtc_state)
>>  		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
>>  }
>>  
>> +static struct drm_property_blob *
>> +icl_read_lut_multi_segment(const struct intel_crtc_state *crtc_state)
>> +{
>> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
>> +	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>> +	int lut_size = INTEL_INFO(dev_priv)->color.gamma_lut_size;
>> +	enum pipe pipe = crtc->pipe;
>> +	struct drm_property_blob *blob;
>> +	struct drm_color_lut *blob_data;
>> +	u32 i, val1, val2;
>> +
>> +	blob = drm_property_create_blob(&dev_priv->drm,
>> +					sizeof(struct drm_color_lut) * lut_size,
>> +					NULL);
>> +	if (IS_ERR(blob))
>> +		return NULL;
>> +
>> +	blob_data = blob->data;
>> +
>> +	I915_WRITE(PREC_PAL_MULTI_SEG_INDEX(pipe), PAL_PREC_AUTO_INCREMENT);
>> +
>> +	for (i = 0; i < 9; i++) {
>> +		val1 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
>> +		val2 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
>> +
>> +		blob_data[i].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
>> +				   REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
>> +		blob_data[i].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
>> +				     REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
>> +		blob_data[i].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
>> +				    REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
>> +	}
>> +
>> +	/*
>> +	 * FIXME readouts from PAL_PREC_DATA register aren't giving correct values
>> +	 * in the case of fine and coarse segments. Restricting readouts only for
>> +	 * super fine segment as of now.
>> +	 */
>> +
>> +	return blob;
>> +}
>> +
>> +static void icl_read_luts(struct intel_crtc_state *crtc_state)
>> +{
>> +	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
>> +		return;
>> +
>> +	if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
>> +	    GAMMA_MODE_MODE_8BIT)
>
> Please make this a switch statement.
>
> I pushed patches 1-2 to dinq. Thanks.
>
>> +		crtc_state->base.gamma_lut = i9xx_read_lut_8(crtc_state);
>> +	else if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
>> +		 GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED)
>> +		crtc_state->base.gamma_lut = icl_read_lut_multi_segment(crtc_state);
>> +	else
>> +		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
>> +}
>> +
>>  void intel_color_init(struct intel_crtc *crtc)
>>  {
>>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>> @@ -1858,6 +1947,7 @@ void intel_color_init(struct intel_crtc *crtc)
>>  
>>  		if (INTEL_GEN(dev_priv) >= 11) {
>>  			dev_priv->display.load_luts = icl_load_luts;
>> +			dev_priv->display.read_luts = icl_read_luts;
>>  		} else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv)) {
>>  			dev_priv->display.load_luts = glk_load_luts;
>>  			dev_priv->display.read_luts = glk_read_luts;
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index 1dc067fc57ab..06b6398b7d62 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -10584,6 +10584,12 @@ enum skl_power_gate {
>>  
>>  #define _PAL_PREC_MULTI_SEG_DATA_A	0x4A40C
>>  #define _PAL_PREC_MULTI_SEG_DATA_B	0x4AC0C
>> +#define  PAL_PREC_MULTI_SEG_RED_LDW_MASK   REG_GENMASK(29, 24)
>> +#define  PAL_PREC_MULTI_SEG_RED_UDW_MASK   REG_GENMASK(29, 20)
>> +#define  PAL_PREC_MULTI_SEG_GREEN_LDW_MASK REG_GENMASK(19, 14)
>> +#define  PAL_PREC_MULTI_SEG_GREEN_UDW_MASK REG_GENMASK(19, 10)
>> +#define  PAL_PREC_MULTI_SEG_BLUE_LDW_MASK  REG_GENMASK(9, 4)
>> +#define  PAL_PREC_MULTI_SEG_BLUE_UDW_MASK  REG_GENMASK(9, 0)
>>  
>>  #define PREC_PAL_MULTI_SEG_INDEX(pipe)	_MMIO_PIPE(pipe, \
>>  					_PAL_PREC_MULTI_SEG_INDEX_A, \
>> -- 
>> 2.23.0
Ville Syrjälä Oct. 15, 2019, 12:34 p.m. UTC | #4
On Thu, Oct 10, 2019 at 04:20:04PM +0530, Sharma, Swati2 wrote:
> On 09-Oct-19 7:46 PM, Ville Syrjälä wrote:
> > On Wed, Oct 09, 2019 at 12:25:41PM +0530, Swati Sharma wrote:
> >> For icl+, have hw read out to create hw blob of gamma
> >> lut values. icl+ platforms supports multi segmented gamma
> >> mode by default, add hw lut creation for this mode.
> >>
> >> This will be used to validate gamma programming using dsb
> >> (display state buffer) which is a tgl specific feature.
> >>
> >> Major change done-removal of readouts of coarse and fine segments
> >> because PAL_PREC_DATA register isn't giving propoer values.
> >> State checker limited only to "fine segment"
> >>
> >> v2: -readout code for multisegmented gamma has to come
> >>       up with some intermediate entries that aren't preserved
> >>       in hardware (Jani N)
> >>      -linear interpolation (Ville)
> >>      -moved common code to check gamma_enable to specific funcs,
> >>       since icl doesn't support that
> >> v3: -use u16 instead of __u16 [Jani N]
> >>      -used single lut [Jani N]
> >>      -improved and more readable for loops [Jani N]
> >>      -read values directly to actual locations and then fill gaps [Jani N]
> >>      -moved cleaning to patch 1 [Jani N]
> >>      -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
> >>       make it similar to icl_load_luts()
> >>      -renamed icl_compute_interpolated_gamma_blob() to
> >>       icl_compute_interpolated_gamma_lut_values() more sensible, I guess
> >> v4: -removed interpolated func for creating gamma lut values
> >>      -removed readouts of fine and coarse segments, failure to read PAL_PREC_DATA
> >>       correctly
> >> v5: -added gamma_enable check inside read_luts()
> >>
> >> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
> >> ---
> >>   drivers/gpu/drm/i915/display/intel_color.c | 114 ++++++++++++++++++---
> >>   drivers/gpu/drm/i915/i915_reg.h            |   6 ++
> >>   2 files changed, 108 insertions(+), 12 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
> >> index fa44eb73d088..614e0ad386ca 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_color.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> >> @@ -1477,6 +1477,25 @@ static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
> >>   	}
> >>   }
> >>   
> >> +static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
> >> +{
> >> +	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
> >> +		return 0;
> >> +
> >> +	switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
> >> +	case GAMMA_MODE_MODE_8BIT:
> >> +		return 8;
> >> +	case GAMMA_MODE_MODE_10BIT:
> >> +		return 10;
> >> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> >> +		return 16;
> >> +	default:
> >> +		MISSING_CASE(crtc_state->gamma_mode);
> >> +		return 0;
> >> +	}
> >> +
> >> +}
> >> +
> >>   int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
> >>   {
> >>   	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
> >> @@ -1488,7 +1507,9 @@ int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_stat
> >>   		else
> >>   			return i9xx_gamma_precision(crtc_state);
> >>   	} else {
> >> -		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
> >> +		if (INTEL_GEN(dev_priv) >= 11)
> >> +			return icl_gamma_precision(crtc_state);
> >> +		else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
> >>   			return glk_gamma_precision(crtc_state);
> >>   		else if (IS_IRONLAKE(dev_priv))
> >>   			return ilk_gamma_precision(crtc_state);
> >> @@ -1519,6 +1540,20 @@ static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
> >>   	return true;
> >>   }
> >>   
> >> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
> >> +					      struct drm_color_lut *lut2,
> >> +					      int lut_size, u32 err)
> >> +{
> >> +	int i;
> >> +
> >> +	for (i = 0; i < 9; i++) {
> >> +		if (!err_check(&lut1[i], &lut2[i], err))
> >> +			return false;
> >> +	}
> >> +
> >> +	return true;
> >> +}
> >> +
> >>   bool intel_color_lut_equal(struct drm_property_blob *blob1,
> >>   			   struct drm_property_blob *blob2,
> >>   			   u32 gamma_mode, u32 bit_precision)
> >> @@ -1537,16 +1572,8 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
> >>   	lut_size2 = drm_color_lut_size(blob2);
> >>   
> >>   	/* check sw and hw lut size */
> >> -	switch (gamma_mode) {
> >> -	case GAMMA_MODE_MODE_8BIT:
> >> -	case GAMMA_MODE_MODE_10BIT:
> >> -		if (lut_size1 != lut_size2)
> >> -			return false;
> >> -		break;
> >> -	default:
> >> -		MISSING_CASE(gamma_mode);
> >> -			return false;
> >> -	}
> >> +	if (lut_size1 != lut_size2)
> >> +		return false;
> >>   
> >>   	lut1 = blob1->data;
> >>   	lut2 = blob2->data;
> >> @@ -1554,13 +1581,18 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
> >>   	err = 0xffff >> bit_precision;
> >>   
> >>   	/* check sw and hw lut entry to be equal */
> >> -	switch (gamma_mode) {
> >> +	switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
> >>   	case GAMMA_MODE_MODE_8BIT:
> >>   	case GAMMA_MODE_MODE_10BIT:
> >>   		if (!intel_color_lut_entry_equal(lut1, lut2,
> >>   						 lut_size2, err))
> >>   			return false;
> >>   		break;
> >> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> >> +		if (!intel_color_lut_entry_multi_equal(lut1, lut2,
> >> +						       lut_size2, err))
> > 
> > I don't think you need a new function for that. Just pass 9 as the size
> > to intel_color_lut_entry_equal() ?
> 
> I had made a separate function for multi-segmented gamma since there 
> will be 3 loops for comparing superfine, fine and course segments which 
> wont go with intel_lut_entry_equal() structure.
> 
> Right now we are limiting to superfine segment only but in future we 
> will add for other segments too (once we get fix from h/w)
> 
> Func() should look like this. Actually there is no need to passing 
> lut_size only in this function if we continue with this function only.
> 
> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
> +                                             struct drm_color_lut *lut2,
> +                                             int lut_size, u32 err)
> +{
> +       int i;
> +
> +       for (i = 0; i < 9; i++) {
> +               if (!err_check(&lut1[i], &lut2[i], err))
> +                       return false;
> +       }
> +
> +       for (i = 1; i < 257; i++) {
> +               if (!err_check(&lut1[i * 8], &lut2[i * 8], err))
> +                       return false;
> +       }
> +
> +       for (i = 0; i < 256; i++) {
> +               if (!err_check(&lut1[i * 8 * 128], &lut2[i * 8 * 128], err))
> +                       return false;
> +       }
> +
> +       return true;
> +}
> +
> Please suggest.

There's not much point in duplicating code until it's proven to
be required. Who knows when the hw gets fixed, maybe never.

> 
> > 
> > Hmm, should probably rename that to just intel_color_lut_equal() since
> > it checks the entire LUT (or at least the specified subset) and not
> > just a single entry...
> 
> This will be fine for this segment but for other two segments it won't 
> work. Right?

We could generalize it to take start+end+stride. Dunno if that would be
particularly beneficial though.
Swati Sharma Oct. 15, 2019, 2:04 p.m. UTC | #5
On 15-Oct-19 6:04 PM, Ville Syrjälä wrote:
> On Thu, Oct 10, 2019 at 04:20:04PM +0530, Sharma, Swati2 wrote:
>> On 09-Oct-19 7:46 PM, Ville Syrjälä wrote:
>>> On Wed, Oct 09, 2019 at 12:25:41PM +0530, Swati Sharma wrote:
>>>> For icl+, have hw read out to create hw blob of gamma
>>>> lut values. icl+ platforms supports multi segmented gamma
>>>> mode by default, add hw lut creation for this mode.
>>>>
>>>> This will be used to validate gamma programming using dsb
>>>> (display state buffer) which is a tgl specific feature.
>>>>
>>>> Major change done-removal of readouts of coarse and fine segments
>>>> because PAL_PREC_DATA register isn't giving propoer values.
>>>> State checker limited only to "fine segment"
>>>>
>>>> v2: -readout code for multisegmented gamma has to come
>>>>        up with some intermediate entries that aren't preserved
>>>>        in hardware (Jani N)
>>>>       -linear interpolation (Ville)
>>>>       -moved common code to check gamma_enable to specific funcs,
>>>>        since icl doesn't support that
>>>> v3: -use u16 instead of __u16 [Jani N]
>>>>       -used single lut [Jani N]
>>>>       -improved and more readable for loops [Jani N]
>>>>       -read values directly to actual locations and then fill gaps [Jani N]
>>>>       -moved cleaning to patch 1 [Jani N]
>>>>       -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
>>>>        make it similar to icl_load_luts()
>>>>       -renamed icl_compute_interpolated_gamma_blob() to
>>>>        icl_compute_interpolated_gamma_lut_values() more sensible, I guess
>>>> v4: -removed interpolated func for creating gamma lut values
>>>>       -removed readouts of fine and coarse segments, failure to read PAL_PREC_DATA
>>>>        correctly
>>>> v5: -added gamma_enable check inside read_luts()
>>>>
>>>> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
>>>> ---
>>>>    drivers/gpu/drm/i915/display/intel_color.c | 114 ++++++++++++++++++---
>>>>    drivers/gpu/drm/i915/i915_reg.h            |   6 ++
>>>>    2 files changed, 108 insertions(+), 12 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
>>>> index fa44eb73d088..614e0ad386ca 100644
>>>> --- a/drivers/gpu/drm/i915/display/intel_color.c
>>>> +++ b/drivers/gpu/drm/i915/display/intel_color.c
>>>> @@ -1477,6 +1477,25 @@ static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
>>>>    	}
>>>>    }
>>>>    
>>>> +static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
>>>> +{
>>>> +	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
>>>> +		return 0;
>>>> +
>>>> +	switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
>>>> +	case GAMMA_MODE_MODE_8BIT:
>>>> +		return 8;
>>>> +	case GAMMA_MODE_MODE_10BIT:
>>>> +		return 10;
>>>> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
>>>> +		return 16;
>>>> +	default:
>>>> +		MISSING_CASE(crtc_state->gamma_mode);
>>>> +		return 0;
>>>> +	}
>>>> +
>>>> +}
>>>> +
>>>>    int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
>>>>    {
>>>>    	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
>>>> @@ -1488,7 +1507,9 @@ int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_stat
>>>>    		else
>>>>    			return i9xx_gamma_precision(crtc_state);
>>>>    	} else {
>>>> -		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
>>>> +		if (INTEL_GEN(dev_priv) >= 11)
>>>> +			return icl_gamma_precision(crtc_state);
>>>> +		else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
>>>>    			return glk_gamma_precision(crtc_state);
>>>>    		else if (IS_IRONLAKE(dev_priv))
>>>>    			return ilk_gamma_precision(crtc_state);
>>>> @@ -1519,6 +1540,20 @@ static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
>>>>    	return true;
>>>>    }
>>>>    
>>>> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
>>>> +					      struct drm_color_lut *lut2,
>>>> +					      int lut_size, u32 err)
>>>> +{
>>>> +	int i;
>>>> +
>>>> +	for (i = 0; i < 9; i++) {
>>>> +		if (!err_check(&lut1[i], &lut2[i], err))
>>>> +			return false;
>>>> +	}
>>>> +
>>>> +	return true;
>>>> +}
>>>> +
>>>>    bool intel_color_lut_equal(struct drm_property_blob *blob1,
>>>>    			   struct drm_property_blob *blob2,
>>>>    			   u32 gamma_mode, u32 bit_precision)
>>>> @@ -1537,16 +1572,8 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>>>>    	lut_size2 = drm_color_lut_size(blob2);
>>>>    
>>>>    	/* check sw and hw lut size */
>>>> -	switch (gamma_mode) {
>>>> -	case GAMMA_MODE_MODE_8BIT:
>>>> -	case GAMMA_MODE_MODE_10BIT:
>>>> -		if (lut_size1 != lut_size2)
>>>> -			return false;
>>>> -		break;
>>>> -	default:
>>>> -		MISSING_CASE(gamma_mode);
>>>> -			return false;
>>>> -	}
>>>> +	if (lut_size1 != lut_size2)
>>>> +		return false;
>>>>    
>>>>    	lut1 = blob1->data;
>>>>    	lut2 = blob2->data;
>>>> @@ -1554,13 +1581,18 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
>>>>    	err = 0xffff >> bit_precision;
>>>>    
>>>>    	/* check sw and hw lut entry to be equal */
>>>> -	switch (gamma_mode) {
>>>> +	switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
>>>>    	case GAMMA_MODE_MODE_8BIT:
>>>>    	case GAMMA_MODE_MODE_10BIT:
>>>>    		if (!intel_color_lut_entry_equal(lut1, lut2,
>>>>    						 lut_size2, err))
>>>>    			return false;
>>>>    		break;
>>>> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
>>>> +		if (!intel_color_lut_entry_multi_equal(lut1, lut2,
>>>> +						       lut_size2, err))
>>>
>>> I don't think you need a new function for that. Just pass 9 as the size
>>> to intel_color_lut_entry_equal() ?
>>
>> I had made a separate function for multi-segmented gamma since there
>> will be 3 loops for comparing superfine, fine and course segments which
>> wont go with intel_lut_entry_equal() structure.
>>
>> Right now we are limiting to superfine segment only but in future we
>> will add for other segments too (once we get fix from h/w)
>>
>> Func() should look like this. Actually there is no need to passing
>> lut_size only in this function if we continue with this function only.
>>
>> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
>> +                                             struct drm_color_lut *lut2,
>> +                                             int lut_size, u32 err)
>> +{
>> +       int i;
>> +
>> +       for (i = 0; i < 9; i++) {
>> +               if (!err_check(&lut1[i], &lut2[i], err))
>> +                       return false;
>> +       }
>> +
>> +       for (i = 1; i < 257; i++) {
>> +               if (!err_check(&lut1[i * 8], &lut2[i * 8], err))
>> +                       return false;
>> +       }
>> +
>> +       for (i = 0; i < 256; i++) {
>> +               if (!err_check(&lut1[i * 8 * 128], &lut2[i * 8 * 128], err))
>> +                       return false;
>> +       }
>> +
>> +       return true;
>> +}
>> +
>> Please suggest.
> 
> There's not much point in duplicating code until it's proven to
> be required. Who knows when the hw gets fixed, maybe never.
Now, got your point. Thanks!
> 
>>
>>>
>>> Hmm, should probably rename that to just intel_color_lut_equal() since
>>> it checks the entire LUT (or at least the specified subset) and not
>>> just a single entry...
Already intel_color_lut_equal() function exits, should i rename that to
intel_color_blob_equal() or intel_color_gamma_blob()? and make this func 
intel_color_lut_entry_equal() to intel_color_lut_equal() as suggested by 
you?
Please comment!
>>
>> This will be fine for this segment but for other two segments it won't
>> work. Right?
> 
> We could generalize it to take start+end+stride. Dunno if that would be
> particularly beneficial though.
>
Ville Syrjälä Oct. 15, 2019, 2:53 p.m. UTC | #6
On Tue, Oct 15, 2019 at 07:34:00PM +0530, Sharma, Swati2 wrote:
> On 15-Oct-19 6:04 PM, Ville Syrjälä wrote:
> > On Thu, Oct 10, 2019 at 04:20:04PM +0530, Sharma, Swati2 wrote:
> >> On 09-Oct-19 7:46 PM, Ville Syrjälä wrote:
> >>> On Wed, Oct 09, 2019 at 12:25:41PM +0530, Swati Sharma wrote:
> >>>> For icl+, have hw read out to create hw blob of gamma
> >>>> lut values. icl+ platforms supports multi segmented gamma
> >>>> mode by default, add hw lut creation for this mode.
> >>>>
> >>>> This will be used to validate gamma programming using dsb
> >>>> (display state buffer) which is a tgl specific feature.
> >>>>
> >>>> Major change done-removal of readouts of coarse and fine segments
> >>>> because PAL_PREC_DATA register isn't giving propoer values.
> >>>> State checker limited only to "fine segment"
> >>>>
> >>>> v2: -readout code for multisegmented gamma has to come
> >>>>        up with some intermediate entries that aren't preserved
> >>>>        in hardware (Jani N)
> >>>>       -linear interpolation (Ville)
> >>>>       -moved common code to check gamma_enable to specific funcs,
> >>>>        since icl doesn't support that
> >>>> v3: -use u16 instead of __u16 [Jani N]
> >>>>       -used single lut [Jani N]
> >>>>       -improved and more readable for loops [Jani N]
> >>>>       -read values directly to actual locations and then fill gaps [Jani N]
> >>>>       -moved cleaning to patch 1 [Jani N]
> >>>>       -renamed icl_read_lut_multi_seg() to icl_read_lut_multi_segment to
> >>>>        make it similar to icl_load_luts()
> >>>>       -renamed icl_compute_interpolated_gamma_blob() to
> >>>>        icl_compute_interpolated_gamma_lut_values() more sensible, I guess
> >>>> v4: -removed interpolated func for creating gamma lut values
> >>>>       -removed readouts of fine and coarse segments, failure to read PAL_PREC_DATA
> >>>>        correctly
> >>>> v5: -added gamma_enable check inside read_luts()
> >>>>
> >>>> Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
> >>>> ---
> >>>>    drivers/gpu/drm/i915/display/intel_color.c | 114 ++++++++++++++++++---
> >>>>    drivers/gpu/drm/i915/i915_reg.h            |   6 ++
> >>>>    2 files changed, 108 insertions(+), 12 deletions(-)
> >>>>
> >>>> diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
> >>>> index fa44eb73d088..614e0ad386ca 100644
> >>>> --- a/drivers/gpu/drm/i915/display/intel_color.c
> >>>> +++ b/drivers/gpu/drm/i915/display/intel_color.c
> >>>> @@ -1477,6 +1477,25 @@ static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
> >>>>    	}
> >>>>    }
> >>>>    
> >>>> +static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
> >>>> +{
> >>>> +	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
> >>>> +		return 0;
> >>>> +
> >>>> +	switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
> >>>> +	case GAMMA_MODE_MODE_8BIT:
> >>>> +		return 8;
> >>>> +	case GAMMA_MODE_MODE_10BIT:
> >>>> +		return 10;
> >>>> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> >>>> +		return 16;
> >>>> +	default:
> >>>> +		MISSING_CASE(crtc_state->gamma_mode);
> >>>> +		return 0;
> >>>> +	}
> >>>> +
> >>>> +}
> >>>> +
> >>>>    int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
> >>>>    {
> >>>>    	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
> >>>> @@ -1488,7 +1507,9 @@ int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_stat
> >>>>    		else
> >>>>    			return i9xx_gamma_precision(crtc_state);
> >>>>    	} else {
> >>>> -		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
> >>>> +		if (INTEL_GEN(dev_priv) >= 11)
> >>>> +			return icl_gamma_precision(crtc_state);
> >>>> +		else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
> >>>>    			return glk_gamma_precision(crtc_state);
> >>>>    		else if (IS_IRONLAKE(dev_priv))
> >>>>    			return ilk_gamma_precision(crtc_state);
> >>>> @@ -1519,6 +1540,20 @@ static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
> >>>>    	return true;
> >>>>    }
> >>>>    
> >>>> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
> >>>> +					      struct drm_color_lut *lut2,
> >>>> +					      int lut_size, u32 err)
> >>>> +{
> >>>> +	int i;
> >>>> +
> >>>> +	for (i = 0; i < 9; i++) {
> >>>> +		if (!err_check(&lut1[i], &lut2[i], err))
> >>>> +			return false;
> >>>> +	}
> >>>> +
> >>>> +	return true;
> >>>> +}
> >>>> +
> >>>>    bool intel_color_lut_equal(struct drm_property_blob *blob1,
> >>>>    			   struct drm_property_blob *blob2,
> >>>>    			   u32 gamma_mode, u32 bit_precision)
> >>>> @@ -1537,16 +1572,8 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
> >>>>    	lut_size2 = drm_color_lut_size(blob2);
> >>>>    
> >>>>    	/* check sw and hw lut size */
> >>>> -	switch (gamma_mode) {
> >>>> -	case GAMMA_MODE_MODE_8BIT:
> >>>> -	case GAMMA_MODE_MODE_10BIT:
> >>>> -		if (lut_size1 != lut_size2)
> >>>> -			return false;
> >>>> -		break;
> >>>> -	default:
> >>>> -		MISSING_CASE(gamma_mode);
> >>>> -			return false;
> >>>> -	}
> >>>> +	if (lut_size1 != lut_size2)
> >>>> +		return false;
> >>>>    
> >>>>    	lut1 = blob1->data;
> >>>>    	lut2 = blob2->data;
> >>>> @@ -1554,13 +1581,18 @@ bool intel_color_lut_equal(struct drm_property_blob *blob1,
> >>>>    	err = 0xffff >> bit_precision;
> >>>>    
> >>>>    	/* check sw and hw lut entry to be equal */
> >>>> -	switch (gamma_mode) {
> >>>> +	switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
> >>>>    	case GAMMA_MODE_MODE_8BIT:
> >>>>    	case GAMMA_MODE_MODE_10BIT:
> >>>>    		if (!intel_color_lut_entry_equal(lut1, lut2,
> >>>>    						 lut_size2, err))
> >>>>    			return false;
> >>>>    		break;
> >>>> +	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
> >>>> +		if (!intel_color_lut_entry_multi_equal(lut1, lut2,
> >>>> +						       lut_size2, err))
> >>>
> >>> I don't think you need a new function for that. Just pass 9 as the size
> >>> to intel_color_lut_entry_equal() ?
> >>
> >> I had made a separate function for multi-segmented gamma since there
> >> will be 3 loops for comparing superfine, fine and course segments which
> >> wont go with intel_lut_entry_equal() structure.
> >>
> >> Right now we are limiting to superfine segment only but in future we
> >> will add for other segments too (once we get fix from h/w)
> >>
> >> Func() should look like this. Actually there is no need to passing
> >> lut_size only in this function if we continue with this function only.
> >>
> >> +static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
> >> +                                             struct drm_color_lut *lut2,
> >> +                                             int lut_size, u32 err)
> >> +{
> >> +       int i;
> >> +
> >> +       for (i = 0; i < 9; i++) {
> >> +               if (!err_check(&lut1[i], &lut2[i], err))
> >> +                       return false;
> >> +       }
> >> +
> >> +       for (i = 1; i < 257; i++) {
> >> +               if (!err_check(&lut1[i * 8], &lut2[i * 8], err))
> >> +                       return false;
> >> +       }
> >> +
> >> +       for (i = 0; i < 256; i++) {
> >> +               if (!err_check(&lut1[i * 8 * 128], &lut2[i * 8 * 128], err))
> >> +                       return false;
> >> +       }
> >> +
> >> +       return true;
> >> +}
> >> +
> >> Please suggest.
> > 
> > There's not much point in duplicating code until it's proven to
> > be required. Who knows when the hw gets fixed, maybe never.
> Now, got your point. Thanks!
> > 
> >>
> >>>
> >>> Hmm, should probably rename that to just intel_color_lut_equal() since
> >>> it checks the entire LUT (or at least the specified subset) and not
> >>> just a single entry...
> Already intel_color_lut_equal() function exits, should i rename that to
> intel_color_blob_equal() or intel_color_gamma_blob()? and make this func 
> intel_color_lut_entry_equal() to intel_color_lut_equal() as suggested by 
> you?

Hmm. In that case I think just s/entry/entries/ would make sense.

Patch
diff mbox series

diff --git a/drivers/gpu/drm/i915/display/intel_color.c b/drivers/gpu/drm/i915/display/intel_color.c
index fa44eb73d088..614e0ad386ca 100644
--- a/drivers/gpu/drm/i915/display/intel_color.c
+++ b/drivers/gpu/drm/i915/display/intel_color.c
@@ -1477,6 +1477,25 @@  static int glk_gamma_precision(const struct intel_crtc_state *crtc_state)
 	}
 }
 
+static int icl_gamma_precision(const struct intel_crtc_state *crtc_state)
+{
+	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
+		return 0;
+
+	switch (crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) {
+	case GAMMA_MODE_MODE_8BIT:
+		return 8;
+	case GAMMA_MODE_MODE_10BIT:
+		return 10;
+	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
+		return 16;
+	default:
+		MISSING_CASE(crtc_state->gamma_mode);
+		return 0;
+	}
+
+}
+
 int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_state)
 {
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
@@ -1488,7 +1507,9 @@  int intel_color_get_gamma_bit_precision(const struct intel_crtc_state *crtc_stat
 		else
 			return i9xx_gamma_precision(crtc_state);
 	} else {
-		if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
+		if (INTEL_GEN(dev_priv) >= 11)
+			return icl_gamma_precision(crtc_state);
+		else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv))
 			return glk_gamma_precision(crtc_state);
 		else if (IS_IRONLAKE(dev_priv))
 			return ilk_gamma_precision(crtc_state);
@@ -1519,6 +1540,20 @@  static bool intel_color_lut_entry_equal(struct drm_color_lut *lut1,
 	return true;
 }
 
+static bool intel_color_lut_entry_multi_equal(struct drm_color_lut *lut1,
+					      struct drm_color_lut *lut2,
+					      int lut_size, u32 err)
+{
+	int i;
+
+	for (i = 0; i < 9; i++) {
+		if (!err_check(&lut1[i], &lut2[i], err))
+			return false;
+	}
+
+	return true;
+}
+
 bool intel_color_lut_equal(struct drm_property_blob *blob1,
 			   struct drm_property_blob *blob2,
 			   u32 gamma_mode, u32 bit_precision)
@@ -1537,16 +1572,8 @@  bool intel_color_lut_equal(struct drm_property_blob *blob1,
 	lut_size2 = drm_color_lut_size(blob2);
 
 	/* check sw and hw lut size */
-	switch (gamma_mode) {
-	case GAMMA_MODE_MODE_8BIT:
-	case GAMMA_MODE_MODE_10BIT:
-		if (lut_size1 != lut_size2)
-			return false;
-		break;
-	default:
-		MISSING_CASE(gamma_mode);
-			return false;
-	}
+	if (lut_size1 != lut_size2)
+		return false;
 
 	lut1 = blob1->data;
 	lut2 = blob2->data;
@@ -1554,13 +1581,18 @@  bool intel_color_lut_equal(struct drm_property_blob *blob1,
 	err = 0xffff >> bit_precision;
 
 	/* check sw and hw lut entry to be equal */
-	switch (gamma_mode) {
+	switch (gamma_mode & GAMMA_MODE_MODE_MASK) {
 	case GAMMA_MODE_MODE_8BIT:
 	case GAMMA_MODE_MODE_10BIT:
 		if (!intel_color_lut_entry_equal(lut1, lut2,
 						 lut_size2, err))
 			return false;
 		break;
+	case GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED:
+		if (!intel_color_lut_entry_multi_equal(lut1, lut2,
+						       lut_size2, err))
+			return false;
+		break;
 	default:
 		MISSING_CASE(gamma_mode);
 			return false;
@@ -1815,6 +1847,63 @@  static void glk_read_luts(struct intel_crtc_state *crtc_state)
 		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
 }
 
+static struct drm_property_blob *
+icl_read_lut_multi_segment(const struct intel_crtc_state *crtc_state)
+{
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+	int lut_size = INTEL_INFO(dev_priv)->color.gamma_lut_size;
+	enum pipe pipe = crtc->pipe;
+	struct drm_property_blob *blob;
+	struct drm_color_lut *blob_data;
+	u32 i, val1, val2;
+
+	blob = drm_property_create_blob(&dev_priv->drm,
+					sizeof(struct drm_color_lut) * lut_size,
+					NULL);
+	if (IS_ERR(blob))
+		return NULL;
+
+	blob_data = blob->data;
+
+	I915_WRITE(PREC_PAL_MULTI_SEG_INDEX(pipe), PAL_PREC_AUTO_INCREMENT);
+
+	for (i = 0; i < 9; i++) {
+		val1 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
+		val2 = I915_READ(PREC_PAL_MULTI_SEG_DATA(pipe));
+
+		blob_data[i].red = REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_UDW_MASK, val2) << 6 |
+				   REG_FIELD_GET(PAL_PREC_MULTI_SEG_RED_LDW_MASK, val1);
+		blob_data[i].green = REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_UDW_MASK, val2) << 6 |
+				     REG_FIELD_GET(PAL_PREC_MULTI_SEG_GREEN_LDW_MASK, val1);
+		blob_data[i].blue = REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_UDW_MASK, val2) << 6 |
+				    REG_FIELD_GET(PAL_PREC_MULTI_SEG_BLUE_LDW_MASK, val1);
+	}
+
+	/*
+	 * FIXME readouts from PAL_PREC_DATA register aren't giving correct values
+	 * in the case of fine and coarse segments. Restricting readouts only for
+	 * super fine segment as of now.
+	 */
+
+	return blob;
+}
+
+static void icl_read_luts(struct intel_crtc_state *crtc_state)
+{
+	if ((crtc_state->gamma_mode & POST_CSC_GAMMA_ENABLE) == 0)
+		return;
+
+	if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
+	    GAMMA_MODE_MODE_8BIT)
+		crtc_state->base.gamma_lut = i9xx_read_lut_8(crtc_state);
+	else if ((crtc_state->gamma_mode & GAMMA_MODE_MODE_MASK) ==
+		 GAMMA_MODE_MODE_12BIT_MULTI_SEGMENTED)
+		crtc_state->base.gamma_lut = icl_read_lut_multi_segment(crtc_state);
+	else
+		crtc_state->base.gamma_lut = glk_read_lut_10(crtc_state, PAL_PREC_INDEX_VALUE(0));
+}
+
 void intel_color_init(struct intel_crtc *crtc)
 {
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
@@ -1858,6 +1947,7 @@  void intel_color_init(struct intel_crtc *crtc)
 
 		if (INTEL_GEN(dev_priv) >= 11) {
 			dev_priv->display.load_luts = icl_load_luts;
+			dev_priv->display.read_luts = icl_read_luts;
 		} else if (IS_CANNONLAKE(dev_priv) || IS_GEMINILAKE(dev_priv)) {
 			dev_priv->display.load_luts = glk_load_luts;
 			dev_priv->display.read_luts = glk_read_luts;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 1dc067fc57ab..06b6398b7d62 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -10584,6 +10584,12 @@  enum skl_power_gate {
 
 #define _PAL_PREC_MULTI_SEG_DATA_A	0x4A40C
 #define _PAL_PREC_MULTI_SEG_DATA_B	0x4AC0C
+#define  PAL_PREC_MULTI_SEG_RED_LDW_MASK   REG_GENMASK(29, 24)
+#define  PAL_PREC_MULTI_SEG_RED_UDW_MASK   REG_GENMASK(29, 20)
+#define  PAL_PREC_MULTI_SEG_GREEN_LDW_MASK REG_GENMASK(19, 14)
+#define  PAL_PREC_MULTI_SEG_GREEN_UDW_MASK REG_GENMASK(19, 10)
+#define  PAL_PREC_MULTI_SEG_BLUE_LDW_MASK  REG_GENMASK(9, 4)
+#define  PAL_PREC_MULTI_SEG_BLUE_UDW_MASK  REG_GENMASK(9, 0)
 
 #define PREC_PAL_MULTI_SEG_INDEX(pipe)	_MMIO_PIPE(pipe, \
 					_PAL_PREC_MULTI_SEG_INDEX_A, \