On Wed, Feb 13, 2019 at 09:45:34AM -0500, David Francis wrote:
> The function intel_compute_rc_parameters is part of the dsc spec
> and is not driver-specific. Other drm drivers might like to use
> it. The function is not changed; just moved and renamed.
>
Yes this sounds fair since its DSC spec related and can move to drm_dsc.c.
As a part of this series or later you should also consider moving the
rc_parameters struct for input bpc/output BPP combinations to DRM since that
is also purely spec related.
With this change and compute_rc_params function in DRM, please add appropriate
description of the function as part of kernel documentation.
With the documentation change, you have my r-b.
Regards
Manasi
> Signed-off-by: David Francis <David.Francis@xxxxxxx>
> ---
> drivers/gpu/drm/drm_dsc.c | 133 ++++++++++++++++++++++++++++++
> drivers/gpu/drm/i915/intel_vdsc.c | 125 +---------------------------
> include/drm/drm_dsc.h | 1 +
> 3 files changed, 135 insertions(+), 124 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_dsc.c b/drivers/gpu/drm/drm_dsc.c
> index bc2b23adb072..4b0e3c9c3ff8 100644
> --- a/drivers/gpu/drm/drm_dsc.c
> +++ b/drivers/gpu/drm/drm_dsc.c
> @@ -11,6 +11,7 @@
> #include <linux/init.h>
> #include <linux/errno.h>
> #include <linux/byteorder/generic.h>
> +#include <drm/drm_print.h>
> #include <drm/drm_dp_helper.h>
> #include <drm/drm_dsc.h>
>
> @@ -226,3 +227,135 @@ void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
> /* PPS 94 - 127 are O */
> }
> EXPORT_SYMBOL(drm_dsc_pps_infoframe_pack);
> +
> +/**
> + * drm_dsc_compute_rc_parameters() - Write rate control
> + * parameters to the dsc configuration. Some configuration
> + * fields must be present beforehand.
> + *
> + * @dsc_cfg:
> + * DSC Configuration data partially filled by driver
> + */
> +int drm_dsc_compute_rc_parameters(struct drm_dsc_config *vdsc_cfg)
> +{
> + unsigned long groups_per_line = 0;
> + unsigned long groups_total = 0;
> + unsigned long num_extra_mux_bits = 0;
> + unsigned long slice_bits = 0;
> + unsigned long hrd_delay = 0;
> + unsigned long final_scale = 0;
> + unsigned long rbs_min = 0;
> +
> + /* Number of groups used to code each line of a slice */
> + groups_per_line = DIV_ROUND_UP(vdsc_cfg->slice_width,
> + DSC_RC_PIXELS_PER_GROUP);
> +
> + /* chunksize in Bytes */
> + vdsc_cfg->slice_chunk_size = DIV_ROUND_UP(vdsc_cfg->slice_width *
> + vdsc_cfg->bits_per_pixel,
> + (8 * 16));
> +
> + if (vdsc_cfg->convert_rgb)
> + num_extra_mux_bits = 3 * (vdsc_cfg->mux_word_size +
> + (4 * vdsc_cfg->bits_per_component + 4)
> + - 2);
> + else
> + num_extra_mux_bits = 3 * vdsc_cfg->mux_word_size +
> + (4 * vdsc_cfg->bits_per_component + 4) +
> + 2 * (4 * vdsc_cfg->bits_per_component) - 2;
> + /* Number of bits in one Slice */
> + slice_bits = 8 * vdsc_cfg->slice_chunk_size * vdsc_cfg->slice_height;
> +
> + while ((num_extra_mux_bits > 0) &&
> + ((slice_bits - num_extra_mux_bits) % vdsc_cfg->mux_word_size))
> + num_extra_mux_bits--;
> +
> + if (groups_per_line < vdsc_cfg->initial_scale_value - 8)
> + vdsc_cfg->initial_scale_value = groups_per_line + 8;
> +
> + /* scale_decrement_interval calculation according to DSC spec 1.11 */
> + if (vdsc_cfg->initial_scale_value > 8)
> + vdsc_cfg->scale_decrement_interval = groups_per_line /
> + (vdsc_cfg->initial_scale_value - 8);
> + else
> + vdsc_cfg->scale_decrement_interval = DSC_SCALE_DECREMENT_INTERVAL_MAX;
> +
> + vdsc_cfg->final_offset = vdsc_cfg->rc_model_size -
> + (vdsc_cfg->initial_xmit_delay *
> + vdsc_cfg->bits_per_pixel + 8) / 16 + num_extra_mux_bits;
> +
> + if (vdsc_cfg->final_offset >= vdsc_cfg->rc_model_size) {
> + DRM_DEBUG_KMS("FinalOfs < RcModelSze for this InitialXmitDelay\n");
> + return -ERANGE;
> + }
> +
> + final_scale = (vdsc_cfg->rc_model_size * 8) /
> + (vdsc_cfg->rc_model_size - vdsc_cfg->final_offset);
> + if (vdsc_cfg->slice_height > 1)
> + /*
> + * NflBpgOffset is 16 bit value with 11 fractional bits
> + * hence we multiply by 2^11 for preserving the
> + * fractional part
> + */
> + vdsc_cfg->nfl_bpg_offset = DIV_ROUND_UP((vdsc_cfg->first_line_bpg_offset << 11),
> + (vdsc_cfg->slice_height - 1));
> + else
> + vdsc_cfg->nfl_bpg_offset = 0;
> +
> + /* 2^16 - 1 */
> + if (vdsc_cfg->nfl_bpg_offset > 65535) {
> + DRM_DEBUG_KMS("NflBpgOffset is too large for this slice height\n");
> + return -ERANGE;
> + }
> +
> + /* Number of groups used to code the entire slice */
> + groups_total = groups_per_line * vdsc_cfg->slice_height;
> +
> + /* slice_bpg_offset is 16 bit value with 11 fractional bits */
> + vdsc_cfg->slice_bpg_offset = DIV_ROUND_UP(((vdsc_cfg->rc_model_size -
> + vdsc_cfg->initial_offset +
> + num_extra_mux_bits) << 11),
> + groups_total);
> +
> + if (final_scale > 9) {
> + /*
> + * ScaleIncrementInterval =
> + * finaloffset/((NflBpgOffset + SliceBpgOffset)*8(finalscale - 1.125))
> + * as (NflBpgOffset + SliceBpgOffset) has 11 bit fractional value,
> + * we need divide by 2^11 from pstDscCfg values
> + */
> + vdsc_cfg->scale_increment_interval =
> + (vdsc_cfg->final_offset * (1 << 11)) /
> + ((vdsc_cfg->nfl_bpg_offset +
> + vdsc_cfg->slice_bpg_offset) *
> + (final_scale - 9));
> + } else {
> + /*
> + * If finalScaleValue is less than or equal to 9, a value of 0 should
> + * be used to disable the scale increment at the end of the slice
> + */
> + vdsc_cfg->scale_increment_interval = 0;
> + }
> +
> + if (vdsc_cfg->scale_increment_interval > 65535) {
> + DRM_DEBUG_KMS("ScaleIncrementInterval is large for slice height\n");
> + return -ERANGE;
> + }
> +
> + /*
> + * DSC spec mentions that bits_per_pixel specifies the target
> + * bits/pixel (bpp) rate that is used by the encoder,
> + * in steps of 1/16 of a bit per pixel
> + */
> + rbs_min = vdsc_cfg->rc_model_size - vdsc_cfg->initial_offset +
> + DIV_ROUND_UP(vdsc_cfg->initial_xmit_delay *
> + vdsc_cfg->bits_per_pixel, 16) +
> + groups_per_line * vdsc_cfg->first_line_bpg_offset;
> +
> + hrd_delay = DIV_ROUND_UP((rbs_min * 16), vdsc_cfg->bits_per_pixel);
> + vdsc_cfg->rc_bits = (hrd_delay * vdsc_cfg->bits_per_pixel) / 16;
> + vdsc_cfg->initial_dec_delay = hrd_delay - vdsc_cfg->initial_xmit_delay;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(drm_dsc_compute_rc_parameters);
> diff --git a/drivers/gpu/drm/i915/intel_vdsc.c b/drivers/gpu/drm/i915/intel_vdsc.c
> index c56ba0e04044..c76cec8bfb74 100644
> --- a/drivers/gpu/drm/i915/intel_vdsc.c
> +++ b/drivers/gpu/drm/i915/intel_vdsc.c
> @@ -318,129 +318,6 @@ static int get_column_index_for_rc_params(u8 bits_per_component)
> }
> }
>
> -static int intel_compute_rc_parameters(struct drm_dsc_config *vdsc_cfg)
> -{
> - unsigned long groups_per_line = 0;
> - unsigned long groups_total = 0;
> - unsigned long num_extra_mux_bits = 0;
> - unsigned long slice_bits = 0;
> - unsigned long hrd_delay = 0;
> - unsigned long final_scale = 0;
> - unsigned long rbs_min = 0;
> -
> - /* Number of groups used to code each line of a slice */
> - groups_per_line = DIV_ROUND_UP(vdsc_cfg->slice_width,
> - DSC_RC_PIXELS_PER_GROUP);
> -
> - /* chunksize in Bytes */
> - vdsc_cfg->slice_chunk_size = DIV_ROUND_UP(vdsc_cfg->slice_width *
> - vdsc_cfg->bits_per_pixel,
> - (8 * 16));
> -
> - if (vdsc_cfg->convert_rgb)
> - num_extra_mux_bits = 3 * (vdsc_cfg->mux_word_size +
> - (4 * vdsc_cfg->bits_per_component + 4)
> - - 2);
> - else
> - num_extra_mux_bits = 3 * vdsc_cfg->mux_word_size +
> - (4 * vdsc_cfg->bits_per_component + 4) +
> - 2 * (4 * vdsc_cfg->bits_per_component) - 2;
> - /* Number of bits in one Slice */
> - slice_bits = 8 * vdsc_cfg->slice_chunk_size * vdsc_cfg->slice_height;
> -
> - while ((num_extra_mux_bits > 0) &&
> - ((slice_bits - num_extra_mux_bits) % vdsc_cfg->mux_word_size))
> - num_extra_mux_bits--;
> -
> - if (groups_per_line < vdsc_cfg->initial_scale_value - 8)
> - vdsc_cfg->initial_scale_value = groups_per_line + 8;
> -
> - /* scale_decrement_interval calculation according to DSC spec 1.11 */
> - if (vdsc_cfg->initial_scale_value > 8)
> - vdsc_cfg->scale_decrement_interval = groups_per_line /
> - (vdsc_cfg->initial_scale_value - 8);
> - else
> - vdsc_cfg->scale_decrement_interval = DSC_SCALE_DECREMENT_INTERVAL_MAX;
> -
> - vdsc_cfg->final_offset = vdsc_cfg->rc_model_size -
> - (vdsc_cfg->initial_xmit_delay *
> - vdsc_cfg->bits_per_pixel + 8) / 16 + num_extra_mux_bits;
> -
> - if (vdsc_cfg->final_offset >= vdsc_cfg->rc_model_size) {
> - DRM_DEBUG_KMS("FinalOfs < RcModelSze for this InitialXmitDelay\n");
> - return -ERANGE;
> - }
> -
> - final_scale = (vdsc_cfg->rc_model_size * 8) /
> - (vdsc_cfg->rc_model_size - vdsc_cfg->final_offset);
> - if (vdsc_cfg->slice_height > 1)
> - /*
> - * NflBpgOffset is 16 bit value with 11 fractional bits
> - * hence we multiply by 2^11 for preserving the
> - * fractional part
> - */
> - vdsc_cfg->nfl_bpg_offset = DIV_ROUND_UP((vdsc_cfg->first_line_bpg_offset << 11),
> - (vdsc_cfg->slice_height - 1));
> - else
> - vdsc_cfg->nfl_bpg_offset = 0;
> -
> - /* 2^16 - 1 */
> - if (vdsc_cfg->nfl_bpg_offset > 65535) {
> - DRM_DEBUG_KMS("NflBpgOffset is too large for this slice height\n");
> - return -ERANGE;
> - }
> -
> - /* Number of groups used to code the entire slice */
> - groups_total = groups_per_line * vdsc_cfg->slice_height;
> -
> - /* slice_bpg_offset is 16 bit value with 11 fractional bits */
> - vdsc_cfg->slice_bpg_offset = DIV_ROUND_UP(((vdsc_cfg->rc_model_size -
> - vdsc_cfg->initial_offset +
> - num_extra_mux_bits) << 11),
> - groups_total);
> -
> - if (final_scale > 9) {
> - /*
> - * ScaleIncrementInterval =
> - * finaloffset/((NflBpgOffset + SliceBpgOffset)*8(finalscale - 1.125))
> - * as (NflBpgOffset + SliceBpgOffset) has 11 bit fractional value,
> - * we need divide by 2^11 from pstDscCfg values
> - */
> - vdsc_cfg->scale_increment_interval =
> - (vdsc_cfg->final_offset * (1 << 11)) /
> - ((vdsc_cfg->nfl_bpg_offset +
> - vdsc_cfg->slice_bpg_offset) *
> - (final_scale - 9));
> - } else {
> - /*
> - * If finalScaleValue is less than or equal to 9, a value of 0 should
> - * be used to disable the scale increment at the end of the slice
> - */
> - vdsc_cfg->scale_increment_interval = 0;
> - }
> -
> - if (vdsc_cfg->scale_increment_interval > 65535) {
> - DRM_DEBUG_KMS("ScaleIncrementInterval is large for slice height\n");
> - return -ERANGE;
> - }
> -
> - /*
> - * DSC spec mentions that bits_per_pixel specifies the target
> - * bits/pixel (bpp) rate that is used by the encoder,
> - * in steps of 1/16 of a bit per pixel
> - */
> - rbs_min = vdsc_cfg->rc_model_size - vdsc_cfg->initial_offset +
> - DIV_ROUND_UP(vdsc_cfg->initial_xmit_delay *
> - vdsc_cfg->bits_per_pixel, 16) +
> - groups_per_line * vdsc_cfg->first_line_bpg_offset;
> -
> - hrd_delay = DIV_ROUND_UP((rbs_min * 16), vdsc_cfg->bits_per_pixel);
> - vdsc_cfg->rc_bits = (hrd_delay * vdsc_cfg->bits_per_pixel) / 16;
> - vdsc_cfg->initial_dec_delay = hrd_delay - vdsc_cfg->initial_xmit_delay;
> -
> - return 0;
> -}
> -
> int intel_dp_compute_dsc_params(struct intel_dp *intel_dp,
> struct intel_crtc_state *pipe_config)
> {
> @@ -575,7 +452,7 @@ int intel_dp_compute_dsc_params(struct intel_dp *intel_dp,
> vdsc_cfg->initial_scale_value = (vdsc_cfg->rc_model_size << 3) /
> (vdsc_cfg->rc_model_size - vdsc_cfg->initial_offset);
>
> - return intel_compute_rc_parameters(vdsc_cfg);
> + return drm_dsc_compute_rc_parameters(vdsc_cfg);
> }
>
> enum intel_display_power_domain
> diff --git a/include/drm/drm_dsc.h b/include/drm/drm_dsc.h
> index d03f1b83421a..ad43494f1cc8 100644
> --- a/include/drm/drm_dsc.h
> +++ b/include/drm/drm_dsc.h
> @@ -481,5 +481,6 @@ struct drm_dsc_pps_infoframe {
> void drm_dsc_dp_pps_header_init(struct drm_dsc_pps_infoframe *pps_sdp);
> void drm_dsc_pps_infoframe_pack(struct drm_dsc_pps_infoframe *pps_sdp,
> const struct drm_dsc_config *dsc_cfg);
> +int drm_dsc_compute_rc_parameters(struct drm_dsc_config *vdsc_cfg);
>
> #endif /* _DRM_DSC_H_ */
> --
> 2.17.1
>
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