[Intel-gfx] [PATCH v2 3/6] drm/i915/vdsc: Add function to read any PPS register

Jani Nikula jani.nikula at linux.intel.com
Thu Jul 13 12:42:54 UTC 2023


On Thu, 13 Jul 2023, Jani Nikula <jani.nikula at linux.intel.com> wrote:
> On Thu, 13 Jul 2023, Suraj Kandpal <suraj.kandpal at intel.com> wrote:
>> Add function to read any PPS register based on the
>> intel_dsc_pps enum provided. Add a function which will call the
>> new pps read function and place it in crtc state. Only PPS0 and
>> PPS1 are readout the rest of the registers will be read in upcoming
>> patches.
>>
>> --v2
>> -Changes in read function as PPS enum is removed
>> -Initialize pps_val as 0 in pps_read func itself [Jani]
>> -Create a function that gets the required register and call that
>> in the common read function [Jani]
>> -Move the drm_WARN_ON one abstraction layer above [Jani]
>>
>> Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
>> ---
>>  drivers/gpu/drm/i915/display/intel_vdsc.c | 276 +++++++++++++++++++---
>>  1 file changed, 242 insertions(+), 34 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_vdsc.c b/drivers/gpu/drm/i915/display/intel_vdsc.c
>> index d48b8306bfc3..48273a3618c5 100644
>> --- a/drivers/gpu/drm/i915/display/intel_vdsc.c
>> +++ b/drivers/gpu/drm/i915/display/intel_vdsc.c
>> @@ -303,6 +303,196 @@ int intel_dsc_get_num_vdsc_instances(const struct intel_crtc_state *crtc_state)
>>  	return num_vdsc_instances;
>>  }
>>  
>> +static void intel_dsc_get_pps_reg(struct intel_crtc_state *crtc_state, int pps,
>> +				  int dsc_eng_no, i915_reg_t *dsc_reg)
>> +{
>> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>> +	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
>> +	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
>> +	enum pipe pipe = crtc->pipe;
>> +	bool pipe_dsc;
>> +
>> +	pipe_dsc = is_pipe_dsc(crtc, cpu_transcoder);
>> +
>> +	switch (pps) {
>> +	case 0:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>
> What's "dsc_eng_no", and why is it 0 or 2?
>
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_0(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_0(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_0;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_0;
>> +		}
>
> I think the branches are backwards here. Above it's DSC1, DSC0 and here
> it's DSCA, DSCC.
>
> I think I'd prefer having
>
> 	if (dsc_eng_no == 0)
>         else
>
> ordering in both.

Actually, reading the patches further, I think it might be better to
always return both registers here. Make this:

static void intel_dsc_get_pps_reg(struct intel_crtc_state *crtc_state,
				  int pps, i915_reg_t *dsc_reg0, i915_reg_t *dsc_reg1)

and it both simplifies and optimizes a lot of places later on.

BR,
Jani.


>
>> +		break;
>> +	case 1:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_1(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_1(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_1;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_1;
>> +		}
>> +		break;
>> +	case 2:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_2(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_2(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_2;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_2;
>> +		}
>> +		break;
>> +	case 3:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_3(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_3(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_3;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_3;
>> +		}
>> +		break;
>> +	case 4:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_4(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_4(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_4;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_4;
>> +		}
>> +		break;
>> +	case 5:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_5(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_5(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_5;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_5;
>> +		}
>> +		break;
>> +	case 6:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_6(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_6(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_6;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_6;
>> +		}
>> +		break;
>> +	case 7:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_7(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_7(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_7;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_7;
>> +		}
>> +		break;
>> +	case 8:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_8(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_8(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_8;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_8;
>> +		}
>> +		break;
>> +	case 9:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_9(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_9(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_9;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_9;
>> +		}
>> +		break;
>> +	case 10:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_10(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_10(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_10;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_10;
>> +		}
>> +		break;
>> +	case 16:
>> +		if (pipe_dsc) {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = ICL_DSC1_PICTURE_PARAMETER_SET_16(pipe);
>> +			else
>> +				*dsc_reg = ICL_DSC0_PICTURE_PARAMETER_SET_16(pipe);
>> +		} else {
>> +			if (dsc_eng_no == 2)
>> +				*dsc_reg = DSCA_PICTURE_PARAMETER_SET_16;
>> +			else
>> +				*dsc_reg = DSCC_PICTURE_PARAMETER_SET_16;
>> +		}
>> +		break;
>> +	/*
>> +	 * Since PPS_17 and PPS_18 were introduced from MTL dsc check
>> +	 * need not be done
>> +	 */
>> +	case 17:
>> +		if (dsc_eng_no == 2)
>> +			*dsc_reg = MTL_DSC1_PICTURE_PARAMETER_SET_17(pipe);
>> +		else
>> +			*dsc_reg = MTL_DSC0_PICTURE_PARAMETER_SET_17(pipe);
>> +		break;
>> +	case 18:
>> +		if (dsc_eng_no == 2)
>> +			*dsc_reg = MTL_DSC1_PICTURE_PARAMETER_SET_18(pipe);
>> +		else
>> +			*dsc_reg = MTL_DSC0_PICTURE_PARAMETER_SET_18(pipe);
>> +		break;
>> +	default:
>> +		drm_err(&i915->drm, "PPS register does not exist\n");
>
> It's a programming error if we hit here. drm_WARN() or MISSING_CASE() or
> something would be better to be loud about it.
>
>> +		break;
>> +	}
>> +}
>> +
>>  static void intel_dsc_pps_configure(const struct intel_crtc_state *crtc_state)
>>  {
>>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>> @@ -930,16 +1120,64 @@ void intel_dsc_disable(const struct intel_crtc_state *old_crtc_state)
>>  	}
>>  }
>>  
>> +static bool intel_dsc_read_pps_reg(struct intel_crtc_state *crtc_state,
>> +				   int pps, u32 *pps_val)
>> +{
>> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>> +	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
>> +	int num_vdsc_instances = intel_dsc_get_num_vdsc_instances(crtc_state);
>> +	i915_reg_t dsc_reg;
>> +	u32 pps_temp;
>> +
>> +	*pps_val = 0;
>> +
>> +	intel_dsc_get_pps_reg(crtc_state, pps, 0, &dsc_reg);
>> +	*pps_val = intel_de_read(i915, dsc_reg);
>> +	if (num_vdsc_instances > 1) {
>> +		intel_dsc_get_pps_reg(crtc_state, pps, 2, &dsc_reg);
>> +		pps_temp = intel_de_read(i915, dsc_reg);
>> +		if (*pps_val != pps_temp)
>> +			return true;
>> +	}
>> +	return false;
>
> I'd really like the dsc reg read function to return the register value,
> instead of returning it through a pointer variable. Dunno how to make it
> work nicely with the verification, though.
>
> Usually functions returning int, ret == 0 means success, and for
> functions returning bool, ret == true means success. Here, ret == true
> means failure, which is kind of backwards.
>
>> +}
>> +
>> +static void intel_dsc_read_and_verify_pps_reg(struct intel_crtc_state *crtc_state,
>> +					      int pps, u32 *pps_val)
>> +{
>> +	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>> +	struct drm_i915_private *i915 = to_i915(crtc->base.dev);
>> +	bool is_dsc_diff;
>> +
>> +	is_dsc_diff = intel_dsc_read_pps_reg(crtc_state, pps, pps_val);
>> +	drm_WARN_ON(&i915->drm, is_dsc_diff);
>> +}
>> +
>> +static void intel_dsc_get_pps_config(struct intel_crtc_state *crtc_state)
>> +{
>> +	struct drm_dsc_config *vdsc_cfg = &crtc_state->dsc.config;
>> +	u32 pps_temp1, pps_temp2;
>> +
>> +	/* Readout PPS_0 and PPS_1 registers */
>> +	intel_dsc_read_and_verify_pps_reg(crtc_state, 0, &pps_temp1);
>> +	intel_dsc_read_and_verify_pps_reg(crtc_state, 1, &pps_temp2);
>> +
>> +	vdsc_cfg->bits_per_pixel = pps_temp2;
>> +
>> +	if (pps_temp1 & DSC_NATIVE_420_ENABLE)
>> +		vdsc_cfg->bits_per_pixel >>= 1;
>> +
>> +	crtc_state->dsc.compressed_bpp = vdsc_cfg->bits_per_pixel >> 4;
>> +}
>> +
>>  void intel_dsc_get_config(struct intel_crtc_state *crtc_state)
>>  {
>>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>>  	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
>> -	struct drm_dsc_config *vdsc_cfg = &crtc_state->dsc.config;
>>  	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
>> -	enum pipe pipe = crtc->pipe;
>>  	enum intel_display_power_domain power_domain;
>>  	intel_wakeref_t wakeref;
>> -	u32 dss_ctl1, dss_ctl2, pps0 = 0, pps1 = 0, pps_temp0 = 0, pps_temp1 = 1;
>> +	u32 dss_ctl1, dss_ctl2;
>>  
>>  	if (!intel_dsc_source_support(crtc_state))
>>  		return;
>> @@ -960,37 +1198,7 @@ void intel_dsc_get_config(struct intel_crtc_state *crtc_state)
>>  	crtc_state->dsc.dsc_split = (dss_ctl2 & RIGHT_BRANCH_VDSC_ENABLE) &&
>>  		(dss_ctl1 & JOINER_ENABLE);
>>  
>> -	/* FIXME: add more state readout as needed */
>> -
>> -	/* PPS0 & PPS1 */
>> -	if (!is_pipe_dsc(crtc, cpu_transcoder)) {
>> -		pps1 = intel_de_read(dev_priv, DSCA_PICTURE_PARAMETER_SET_1);
>> -		if (crtc_state->dsc.dsc_split) {
>> -			pps_temp1 = intel_de_read(dev_priv, DSCC_PICTURE_PARAMETER_SET_1);
>> -			drm_WARN_ON(&dev_priv->drm, pps1 != pps_temp1);
>> -		}
>> -
>> -	} else {
>> -		pps0 = intel_de_read(dev_priv,
>> -				     ICL_DSC0_PICTURE_PARAMETER_SET_0(pipe));
>> -		pps1 = intel_de_read(dev_priv,
>> -				     ICL_DSC0_PICTURE_PARAMETER_SET_1(pipe));
>> -		if (crtc_state->dsc.dsc_split) {
>> -			pps_temp0 = intel_de_read(dev_priv,
>> -						  ICL_DSC0_PICTURE_PARAMETER_SET_0(pipe));
>> -			pps_temp1 = intel_de_read(dev_priv,
>> -						  ICL_DSC0_PICTURE_PARAMETER_SET_1(pipe));
>> -			drm_WARN_ON(&dev_priv->drm, pps0 != pps_temp0);
>> -			drm_WARN_ON(&dev_priv->drm, pps1 != pps_temp1);
>> -		}
>> -	}
>> -
>> -	vdsc_cfg->bits_per_pixel = pps1;
>> -
>> -	if (pps0 & DSC_NATIVE_420_ENABLE)
>> -		vdsc_cfg->bits_per_pixel >>= 1;
>> -
>> -	crtc_state->dsc.compressed_bpp = vdsc_cfg->bits_per_pixel >> 4;
>> +	intel_dsc_get_pps_config(crtc_state);
>>  out:
>>  	intel_display_power_put(dev_priv, power_domain, wakeref);
>>  }

-- 
Jani Nikula, Intel Open Source Graphics Center


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