Re: [Intel-gfx] [RFC 11/13] drm/i915: Read DSC capabilities of the HDMI2.1 PCON encoder

["Nautiyal, Ankit K" <ankit.k.nautiyal@intel.com>]

On 10/19/2020 5:04 AM, Shankar, Uma wrote:
>
>> -----Original Message-----
>> From: Shankar, Uma
>> Sent: Monday, October 19, 2020 5:02 AM
>> To: Nautiyal, Ankit K <ankit.k.nautiyal@intel.com>; intel-
>> gfx@lists.freedesktop.org
>> Cc: dri-devel@lists.freedesktop.org; Kulkarni, Vandita
>> <vandita.kulkarni@intel.com>; ville.syrjala@linux.intel.com; Sharma, Swati2
>> <swati2.sharma@intel.com>
>> Subject: RE: [RFC 11/13] drm/i915: Read DSC capabilities of the HDMI2.1 PCON
>> encoder
> Also it would be good to move to DRM Core.


Agreed, as mentioned in earlier patch, will move the appropriate code as 
drm_helper functions.


Regards,

Ankit

>
>>
>>> -----Original Message-----
>>> From: Nautiyal, Ankit K <ankit.k.nautiyal@intel.com>
>>> Sent: Thursday, October 15, 2020 4:23 PM
>>> To: intel-gfx@lists.freedesktop.org
>>> Cc: dri-devel@lists.freedesktop.org; Shankar, Uma
>>> <uma.shankar@intel.com>; Kulkarni, Vandita
>>> <vandita.kulkarni@intel.com>; ville.syrjala@linux.intel.com; Sharma,
>>> Swati2 <swati2.sharma@intel.com>
>>> Subject: [RFC 11/13] drm/i915: Read DSC capabilities of the HDMI2.1
>>> PCON encoder
>>>
>>> This patch adds a helper function to read the DSC capabilities of the
>>> HDMI2.1 PCon encoder. It also adds a new structure to store these
>>> caps, which can then be used to get the PPS parameters for
>>> PCON-HDMI2.1 sink pair. Which inturn will be used to take a call to
>>> override the existing PPS-metadata, by either writing the entire new
>>> PPS metadata, or by writing only the PPS override parameters.
>>>
>>> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
>>> ---
>>>   .../drm/i915/display/intel_display_types.h    |  16 ++
>>>   drivers/gpu/drm/i915/display/intel_dp.c       | 178 ++++++++++++++++++
>>>   2 files changed, 194 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
>>> b/drivers/gpu/drm/i915/display/intel_display_types.h
>>> index 6c69922313d6..23282695a47f 100644
>>> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
>>> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
>>> @@ -1292,6 +1292,21 @@ struct intel_dp_pcon_frl {
>>>   	int trained_rate_gbps;
>>>   };
>>>
>>> +struct intel_dp_pcon_dsc {
>>> +	bool enc_support;
>>> +	bool pps_override_support;
>>> +	bool blk_prediction_support;
>>> +	u8 version_major;
>>> +	u8 version_minor;
>>> +	u8 color_fmt_mask;
>>> +	u8 color_depth_mask;
>>> +	u8 max_slices;;
>>> +	u8 max_slice_width;
>>> +	u8 line_buf_bit_depth;
>>> +	u8 bpp_precision_incr;
>>> +	int rc_buf_size;
>>> +};
>>> +
>>>   struct intel_dp {
>>>   	i915_reg_t output_reg;
>>>   	u32 DP;
>>> @@ -1415,6 +1430,7 @@ struct intel_dp {
>>>   	bool hobl_active;
>>>
>>>   	struct intel_dp_pcon_frl frl;
>>> +	struct intel_dp_pcon_dsc pcon_dsc;
>>>   };
>>>
>>>   enum lspcon_vendor {
>>> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c
>>> b/drivers/gpu/drm/i915/display/intel_dp.c
>>> index e6c4cb844e37..b4f8abaea607 100644
>>> --- a/drivers/gpu/drm/i915/display/intel_dp.c
>>> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
>>> @@ -3882,6 +3882,182 @@ cpt_set_link_train(struct intel_dp *intel_dp,
>>>   	intel_de_posting_read(dev_priv, intel_dp->output_reg);  }
>>>
>>> +void intel_dp_get_pcon_dsc_cap(struct intel_dp *intel_dp) {
>>> +	u8 buf;
>>> +	u8 rc_buf_blk_size;
>>> +	u8 max_slices = 0;
>>> +
>>> +	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
>>> +	struct intel_dp_pcon_dsc *pcon_dsc = &intel_dp->pcon_dsc;
>>> +
>>> +	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_ENCODER, &buf)
>>> < 0) {
>>> +		drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_ENCODER\n");
>>> +		return;
>>> +	}
>>> +	pcon_dsc->enc_support = buf & DP_PCON_DSC_ENCODER_SUPPORTED;
>>> +	pcon_dsc->pps_override_support = buf &
>>> DP_PCON_DSC_PPS_ENC_OVERRIDE;
>>> +
>>> +	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_VERSION, &buf)
>>> < 0) {
>>> +		drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_VERSION\n");
>>> +		return;
>> If we fail here or in any of the subsequent calls below shouldn't we reset the dsc
>> params saying DSC not supported. Else we may return with ex.
>> pcon_dsc->enc_support = buf & DP_PCON_DSC_ENCODER_SUPPORTED which
>> would ideally not be right.
>>
>>> +	}
>>> +	pcon_dsc->version_major = (buf & DP_PCON_DSC_MAJOR_MASK) >>
>>> +				  DP_PCON_DSC_MAJOR_SHIFT;
>>> +	pcon_dsc->version_minor = (buf & DP_PCON_DSC_MINOR_MASK) >>
>>> +				  DP_PCON_DSC_MINOR_SHIFT;
>>> +
>>> +	if (drm_dp_dpcd_readb(&intel_dp->aux,
>>> DP_PCON_DSC_RC_BUF_BLK_INFO, &buf) < 0) {
>>> +		drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_RC_BUF_BLK_INFO\n");
>>> +		return;
>>> +	}
>>> +
>>> +	switch (buf & DP_PCON_DSC_RC_BUF_BLK_SIZE) {
>>> +	case DP_PCON_DSC_RC_BUF_BLK_1KB :
>>> +		rc_buf_blk_size = 1;
>>> +		break;
>>> +	case DP_PCON_DSC_RC_BUF_BLK_4KB :
>>> +		rc_buf_blk_size = 4;
>>> +		break;
>>> +	case DP_PCON_DSC_RC_BUF_BLK_16KB :
>>> +		rc_buf_blk_size = 16;
>>> +		break;
>>> +	case DP_PCON_DSC_RC_BUF_BLK_64KB :
>>> +		rc_buf_blk_size = 64;
>>> +		break;
>>> +	default :
>>> +		rc_buf_blk_size = 0;
>>> +	}
>> It would be good if you create sub-functions for each of these aspects to make it
>> more readable.
>>
>>> +	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_RC_BUF_SIZE,
>>> &buf) < 0) {
>>> +		drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_RC_BUF_SIZE\n");
>>> +		return;
>>> +	}
>>> +	/* storing rc_buf_size in bytes */
>>> +	pcon_dsc->rc_buf_size = (buf + 1) * rc_buf_blk_size * 1024;
>>> +
>>> +	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_SLICE_CAP_2,
>>> &buf) < 0) {
>>> +		drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_SLICE_CAP_2\n");
>>> +		return;
>>> +	}
>>> +	if (buf & DP_PCON_DSC_24_PER_DSC_ENC)
>>> +	       max_slices = 24;
>>> +	else if (buf & DP_PCON_DSC_20_PER_DSC_ENC)
>>> +		max_slices = 20;
>>> +	else if (buf & DP_PCON_DSC_16_PER_DSC_ENC)
>>> +		max_slices = 16;
>>> +
>>> +	if (max_slices == 0) {
>>> +		if (drm_dp_dpcd_readb(&intel_dp->aux,
>>> DP_PCON_DSC_SLICE_CAP_1,
>>> +				      &buf) < 0) {
>>> +			drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_SLICE_CAP_2\n");
>> Its SLICE_CAP_1.
>>
>>> +			return;
>>> +		}
>>> +
>>> +		if (buf & DP_PCON_DSC_12_PER_DSC_ENC)
>>> +			max_slices = 12;
>>> +		else if (buf & DP_PCON_DSC_10_PER_DSC_ENC)
>>> +			max_slices = 10;
>>> +		else if (buf & DP_PCON_DSC_8_PER_DSC_ENC)
>>> +			max_slices = 8;
>>> +		else if (buf & DP_PCON_DSC_6_PER_DSC_ENC)
>>> +			max_slices = 6;
>>> +		else if (buf & DP_PCON_DSC_4_PER_DSC_ENC)
>>> +			max_slices = 4;
>>> +		else if (buf & DP_PCON_DSC_2_PER_DSC_ENC)
>>> +			max_slices = 2;
>>> +		else if (buf & DP_PCON_DSC_1_PER_DSC_ENC)
>>> +			max_slices = 1;
>> Use switch here as well.
>>
>>> +	}
>>> +
>>> +	pcon_dsc->max_slices = max_slices;
>>> +
>>> +	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_BUF_BIT_DEPTH,
>>> &buf) < 0) {
>>> +		drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_BUF_BIT_DEPTH\n");
>>> +		return;
>>> +	}
>>> +	switch (buf & DP_PCON_DSC_BIT_DEPTH_MASK) {
>>> +	case DP_PCON_DSC_DEPTH_8_BITS :
>>> +		pcon_dsc->line_buf_bit_depth = 8;
>>> +		break;
>>> +	case DP_PCON_DSC_DEPTH_9_BITS :
>>> +		pcon_dsc->line_buf_bit_depth = 9;
>>> +		break;
>>> +	case DP_PCON_DSC_DEPTH_10_BITS :
>>> +		pcon_dsc->line_buf_bit_depth = 10;
>>> +		break;
>>> +	case DP_PCON_DSC_DEPTH_11_BITS :
>>> +		pcon_dsc->line_buf_bit_depth = 11;
>>> +		break;
>>> +	case DP_PCON_DSC_DEPTH_12_BITS :
>>> +		pcon_dsc->line_buf_bit_depth = 12;
>>> +		break;
>>> +	case DP_PCON_DSC_DEPTH_13_BITS :
>>> +		pcon_dsc->line_buf_bit_depth = 13;
>>> +		break;
>>> +	case DP_PCON_DSC_DEPTH_14_BITS :
>>> +		pcon_dsc->line_buf_bit_depth = 14;
>>> +		break;
>>> +	case DP_PCON_DSC_DEPTH_15_BITS :
>>> +		pcon_dsc->line_buf_bit_depth = 15;
>>> +		break;
>>> +	case DP_PCON_DSC_DEPTH_16_BITS :
>>> +		pcon_dsc->line_buf_bit_depth = 16;
>>> +		break;
>>> +	default :
>>> +		pcon_dsc->line_buf_bit_depth = 0;
>>> +	}
>>> +
>>> +	if (drm_dp_dpcd_readb(&intel_dp->aux,
>>> DP_PCON_DSC_BLOCK_PREDICTION, &buf) < 0) {
>>> +		drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_BLOCK_PREDICTION\n");
>>> +		return;
>>> +	}
>>> +	if (buf && DP_PCON_DSC_BLOCK_PRED_SUPPORT)
>>> +		pcon_dsc->blk_prediction_support = true;
>>> +
>>> +	if (drm_dp_dpcd_readb(&intel_dp->aux,
>>> DP_PCON_DSC_ENC_COLOR_FMT_CAP, &buf) < 0) {
>>> +		drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_ENC_COLOR_FMT_CAP\n");
>>> +		return;
>>> +	}
>>> +	pcon_dsc->color_fmt_mask = buf;
>>> +
>>> +	if (drm_dp_dpcd_readb(&intel_dp->aux,
>>> DP_PCON_DSC_ENC_COLOR_DEPTH_CAP, &buf) < 0) {
>>> +		drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_ENC_COLOR_DEPTH_CAP\n");
>>> +		return;
>>> +	}
>>> +	pcon_dsc->color_depth_mask = buf;
>>> +
>>> +	if (drm_dp_dpcd_readb(&intel_dp->aux,
>>> DP_PCON_DSC_MAX_SLICE_WIDTH, &buf) < 0) {
>>> +		drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_MAX_SLICE_WIDTH\n");
>>> +		return;
>>> +	}
>>> +	pcon_dsc->max_slice_width = buf;;
>>> +
>>> +	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_PCON_DSC_BPP_INCR, &buf)
>>> < 0) {
>>> +		drm_err(&i915->drm, "Failed to read
>>> DP_PCON_DSC_BPP_INCR\n");
>>> +		return;
>>> +	}
>>> +	switch(buf & DP_PCON_DSC_BPP_INCR_MASK) {
>>> +	case DP_PCON_DSC_ONE_16TH_BPP:
>>> +		pcon_dsc->bpp_precision_incr = 16;
>>> +		break;
>>> +	case DP_PCON_DSC_ONE_8TH_BPP:
>>> +		pcon_dsc->bpp_precision_incr = 8;
>>> +		break;
>>> +	case DP_PCON_DSC_ONE_4TH_BPP:
>>> +		pcon_dsc->bpp_precision_incr = 4;
>>> +		break;
>>> +	case DP_PCON_DSC_ONE_HALF_BPP:
>>> +		pcon_dsc->bpp_precision_incr = 2;
>>> +		break;
>>> +	case DP_PCON_DSC_ONE_BPP:
>>> +		pcon_dsc->bpp_precision_incr = 1;
>>> +		break;
>>> +	default :
>>> +		pcon_dsc->bpp_precision_incr = 0;
>>> +	}
>>> +}
>>> +
>>>   static int intel_dp_get_max_rate_gbps(struct intel_dp *intel_dp)  {
>>>   	int max_link_clock, max_lanes, max_rate_khz, max_rate_gbps; @@ -
>>> 6659,6 +6835,8 @@ intel_dp_update_dfp(struct intel_dp *intel_dp,
>>>   		    intel_dp->dfp.max_tmds_clock,
>>>   		    intel_dp->dfp.pcon_max_frl,
>>>   		    intel_dp->dfp.sink_max_frl);
>>> +
>>> +	intel_dp_get_pcon_dsc_cap(intel_dp);
>>>   }
>>>
>>>   static void
>>> --
>>> 2.17.1
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