On Tue, Nov 06, 2018 at 07:00:50PM +0200, Ville Syrjälä wrote: > On Tue, Nov 06, 2018 at 08:52:41AM -0800, Manasi Navare wrote: > > On Tue, Nov 06, 2018 at 04:33:38PM +0200, Ville Syrjälä wrote: > > > On Fri, Nov 02, 2018 at 02:31:29PM -0700, Manasi Navare wrote: > > > > From: Gaurav K Singh <gaurav.k.si...@intel.com> > > > > > > > > This computation of RC params happens in the atomic commit phase > > > > during compute_config() to validate if display stream compression > > > > can be enabled for the requested mode. > > > > > > > > v7 (From Manasi): > > > > * Use DRM_DEBUG instead of DRM_ERROR (Ville) > > > > * Use Error numberinstead of -1 (Ville) > > > > v6 (From Manasi): > > > > * Use 9 instead of 0x9 for consistency (Anusha) > > > > > > > > v5 (From Manasi): > > > > * Fix dim checkpatch warnings/checks > > > > v4(From Gaurav): > > > > * No change.Rebase on drm-tip > > > > > > > > v3 (From Gaurav): > > > > * Rebase on top of Manasi's latest series > > > > * Return -ve value in case of failure scenarios (Manasi) > > > > > > > > Fix review comments from Ville: > > > > * Remove unnecessary comments > > > > * Remove unnecessary paranthesis > > > > * Add comments for few RC params calculations > > > > > > > > v2 (From Manasi): > > > > * Rebase Gaurav's patch from intel-gfx to gfx-internal > > > > * Use struct drm_dsc_cfg instead of struct intel_dp > > > > as a parameter > > > > > > > > Cc: Manasi Navare <manasi.d.nav...@intel.com> > > > > Cc: Jani Nikula <jani.nik...@linux.intel.com> > > > > Cc: Ville Syrjala <ville.syrj...@linux.intel.com> > > > > Signed-off-by: Gaurav K Singh <gaurav.k.si...@intel.com> > > > > Signed-off-by: Manasi Navare <manasi.d.nav...@intel.com> > > > > Reviewed-by: Anusha Srivatsa <anusha.sriva...@intel.com> > > > > --- > > > > drivers/gpu/drm/i915/intel_vdsc.c | 127 ++++++++++++++++++++++++++++++ > > > > 1 file changed, 127 insertions(+) > > > > > > > > diff --git a/drivers/gpu/drm/i915/intel_vdsc.c > > > > b/drivers/gpu/drm/i915/intel_vdsc.c > > > > index 0a1918f2f643..a76f78b9c0ee 100644 > > > > --- a/drivers/gpu/drm/i915/intel_vdsc.c > > > > +++ b/drivers/gpu/drm/i915/intel_vdsc.c > > > > @@ -317,6 +317,130 @@ 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 -EINVAL; > > > > + } > > > > + > > > > + 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 -EINVAL; > > > > + } > > > > + > > > > + /* 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 -EINVAL; > > > > + } > > > > + > > > > + /* > > > > + * 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) > > > > { > > > > @@ -451,5 +575,8 @@ 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); > > > > > > > > + if (intel_compute_rc_parameters(vdsc_cfg) < 0) > > > > + return -EINVAL; > > > > > > One should pretty much always pass on the errno rather than inventing a > > > new one on the spot. > > > > But compute_rc_parameters() function returns EINVAL everywhere for error > > cases > > Why should I have to know that?
After doing errno --list and looking at the available errnos, the most logical ones to return from intel_compute_rc_parameters is ERANGE since the errors are because the parameters of out of valid range. And here I can just do return intel_compute_rc_parameters() Does this look good? Manasi > > -- > Ville Syrjälä > Intel _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel