[Intel-gfx] [PATCH v3 13/13] drm/i915/dsi: add support for DSC

[Kulkarni, Vandita]

> -----Original Message-----
> From: Jani Nikula <jani.nikula at intel.com>
> Sent: Tuesday, November 26, 2019 7:13 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: Nikula, Jani <jani.nikula at intel.com>; Kulkarni, Vandita
> <vandita.kulkarni at intel.com>; Ville Syrjälä <ville.syrjala at linux.intel.com>
> Subject: [PATCH v3 13/13] drm/i915/dsi: add support for DSC
> 
> Enable DSC for DSI, if specified in VBT.
> 
> This still lacks DSC aware get config implementation, and therefore state
> checker will fail. Also mode valid is not there yet.
> 
> v4:
> - convert_rgb = true (Vandita)
> - ignore max cdclock check (Vandita)
> - rename pipe_config to crtc_state
> 
> v3:
> - take compressed bpp into account
> 
> v2:
> - Nuke conn_state->max_requested_bpc, it's not used on DSI
> 
> Bspec: 49263
> Cc: Vandita Kulkarni <vandita.kulkarni at intel.com>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/display/icl_dsi.c | 67 ++++++++++++++++++++++++--
>  1 file changed, 64 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c
> b/drivers/gpu/drm/i915/display/icl_dsi.c
> index caa477c4b1af..e142ac64f680 100644
> --- a/drivers/gpu/drm/i915/display/icl_dsi.c
> +++ b/drivers/gpu/drm/i915/display/icl_dsi.c
> @@ -34,6 +34,7 @@
>  #include "intel_ddi.h"
>  #include "intel_dsi.h"
>  #include "intel_panel.h"
> +#include "intel_vdsc.h"
> 
>  static inline int header_credits_available(struct drm_i915_private *dev_priv,
>  					   enum transcoder dsi_trans)
> @@ -1087,6 +1088,8 @@ static void gen11_dsi_pre_enable(struct
> intel_encoder *encoder,
>  	/* step5: program and powerup panel */
>  	gen11_dsi_powerup_panel(encoder);
> 
> +	intel_dsc_enable(encoder, pipe_config);
> +
>  	/* step6c: configure transcoder timings */
>  	gen11_dsi_set_transcoder_timings(encoder, pipe_config);
> 
> @@ -1248,6 +1251,13 @@ static void gen11_dsi_disable(struct
> intel_encoder *encoder,
>  	gen11_dsi_disable_io_power(encoder);
>  }
> 
> +static enum drm_mode_status gen11_dsi_mode_valid(struct
> drm_connector *connector,
> +						 struct drm_display_mode
> *mode)
> +{
> +	/* FIXME: DSC? */
> +	return intel_dsi_mode_valid(connector, mode); }
> +
>  static void gen11_dsi_get_timings(struct intel_encoder *encoder,
>  				  struct intel_crtc_state *pipe_config)  { @@ -
> 1295,6 +1305,48 @@ static void gen11_dsi_get_config(struct intel_encoder
> *encoder,
>  	pipe_config->pipe_bpp = bdw_get_pipemisc_bpp(crtc);  }
> 
> +static int gen11_dsi_dsc_compute_config(struct intel_encoder *encoder,
> +					struct intel_crtc_state *crtc_state) {
> +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> +	struct drm_dsc_config *vdsc_cfg = &crtc_state->dsc.config;
> +	int dsc_max_bpc = INTEL_GEN(dev_priv) >= 12 ? 12 : 10;
> +	bool use_dsc;
> +	int ret;
> +
> +	use_dsc = intel_bios_get_dsc_params(encoder, crtc_state,
> dsc_max_bpc);
> +	if (!use_dsc)
> +		return 0;
> +
> +	if (crtc_state->pipe_bpp < 8 * 3)
> +		return -EINVAL;
> +
> +	/* FIXME: split only when necessary */
> +	if (crtc_state->dsc.slice_count > 1)
> +		crtc_state->dsc.dsc_split = true;
> +
> +	vdsc_cfg->convert_rgb = true;
> +

Is there a chance this might fail and pipe_config->bpp might remain changed as per what happens in intel_bios_get_dsc_params?

> +	ret = intel_dsc_compute_params(encoder, crtc_state);
> +	if (ret)
> +		return ret;
> +
> +	/* DSI specific sanity checks on the common code */
> +	WARN_ON(vdsc_cfg->vbr_enable);
> +	WARN_ON(vdsc_cfg->simple_422);
> +	WARN_ON(vdsc_cfg->pic_width % vdsc_cfg->slice_width);
> +	WARN_ON(vdsc_cfg->slice_height < 8);
> +	WARN_ON(vdsc_cfg->pic_height % vdsc_cfg->slice_height);
> +
> +	ret = drm_dsc_compute_rc_parameters(vdsc_cfg);
> +	if (ret)
> +		return ret;
> +
> +	crtc_state->dsc.compression_enable = true;
> +
> +	return 0;
> +}
> +
>  static int gen11_dsi_compute_config(struct intel_encoder *encoder,
>  				    struct intel_crtc_state *pipe_config,
>  				    struct drm_connector_state *conn_state)
> @@ -1326,6 +1378,10 @@ static int gen11_dsi_compute_config(struct
> intel_encoder *encoder,
>  		pipe_config->pipe_bpp = 18;
> 
>  	pipe_config->clock_set = true;
> +
> +	if (gen11_dsi_dsc_compute_config(encoder, pipe_config))
> +		DRM_DEBUG_KMS("Attempting to use DSC failed\n");
> +
>  	pipe_config->port_clock = afe_clk(encoder, pipe_config) / 5;
> 
>  	return 0;
> @@ -1334,8 +1390,13 @@ static int gen11_dsi_compute_config(struct
> intel_encoder *encoder,  static void gen11_dsi_get_power_domains(struct
> intel_encoder *encoder,
>  					struct intel_crtc_state *crtc_state)  {
> -	get_dsi_io_power_domains(to_i915(encoder->base.dev),
> -				 enc_to_intel_dsi(&encoder->base));
> +	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
> +
> +	get_dsi_io_power_domains(i915, enc_to_intel_dsi(&encoder-
> >base));
> +
> +	if (crtc_state->dsc.compression_enable)
> +		intel_display_power_get(i915,
> +
> 	intel_dsc_power_domain(crtc_state));
>  }
> 
>  static bool gen11_dsi_get_hw_state(struct intel_encoder *encoder, @@ -
> 1405,7 +1466,7 @@ static const struct drm_connector_funcs
> gen11_dsi_connector_funcs = {
> 
>  static const struct drm_connector_helper_funcs
> gen11_dsi_connector_helper_funcs = {
>  	.get_modes = intel_dsi_get_modes,
> -	.mode_valid = intel_dsi_mode_valid,
> +	.mode_valid = gen11_dsi_mode_valid,
>  	.atomic_check = intel_digital_connector_atomic_check,
>  };
> 
> --
> 2.20.1