[PATCH v3 3/3] drm/amd/display: Skip modeset for front porch change

Shashank Sharma shashank.sharma at amd.com
Tue Dec 15 04:10:29 UTC 2020


On 15/12/20 3:50 am, Aurabindo Pillai wrote:
> [Why&How]
> Inorder to enable freesync video mode, driver adds extra
> modes based on preferred modes for common freesync frame rates.
> When commiting these mode changes, a full modeset is not needed.
> If the change in only in the front porch timing value, skip full
> modeset and continue using the same stream.
>
> Signed-off-by: Aurabindo Pillai <aurabindo.pillai at amd.com>
> Acked-by: Christian König <christian.koenig at amd.com>
> ---
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 210 +++++++++++++++---
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |   1 +
>  2 files changed, 179 insertions(+), 32 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index c1ffd33e9d83..4ba6be59dcd5 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -213,6 +213,9 @@ static bool amdgpu_dm_psr_disable_all(struct amdgpu_display_manager *dm);
>  static const struct drm_format_info *
>  amd_get_format_info(const struct drm_mode_fb_cmd2 *cmd);
>  
> +static bool
> +is_timing_unchanged_for_freesync(struct drm_crtc_state *old_crtc_state,
> +				 struct drm_crtc_state *new_crtc_state);
Do we need this forward declaration for a static function ?
>  /*
>   * dm_vblank_get_counter
>   *
> @@ -4940,7 +4943,8 @@ static void fill_stream_properties_from_drm_display_mode(
>  	const struct drm_connector *connector,
>  	const struct drm_connector_state *connector_state,
>  	const struct dc_stream_state *old_stream,
> -	int requested_bpc)
> +	int requested_bpc,
> +	bool is_in_modeset)
>  {
>  	struct dc_crtc_timing *timing_out = &stream->timing;
>  	const struct drm_display_info *info = &connector->display_info;
> @@ -4995,19 +4999,28 @@ static void fill_stream_properties_from_drm_display_mode(
>  		timing_out->hdmi_vic = hv_frame.vic;
>  	}
>  
> -	timing_out->h_addressable = mode_in->crtc_hdisplay;
> -	timing_out->h_total = mode_in->crtc_htotal;
> -	timing_out->h_sync_width =
> -		mode_in->crtc_hsync_end - mode_in->crtc_hsync_start;
> -	timing_out->h_front_porch =
> -		mode_in->crtc_hsync_start - mode_in->crtc_hdisplay;
> -	timing_out->v_total = mode_in->crtc_vtotal;
> -	timing_out->v_addressable = mode_in->crtc_vdisplay;
> -	timing_out->v_front_porch =
> -		mode_in->crtc_vsync_start - mode_in->crtc_vdisplay;
> -	timing_out->v_sync_width =
> -		mode_in->crtc_vsync_end - mode_in->crtc_vsync_start;
> -	timing_out->pix_clk_100hz = mode_in->crtc_clock * 10;
> +	if (is_in_modeset) {
> +		timing_out->h_addressable = mode_in->hdisplay;
> +		timing_out->h_total = mode_in->htotal;
> +		timing_out->h_sync_width = mode_in->hsync_end - mode_in->hsync_start;
> +		timing_out->h_front_porch = mode_in->hsync_start - mode_in->hdisplay;
> +		timing_out->v_total = mode_in->vtotal;
> +		timing_out->v_addressable = mode_in->vdisplay;
> +		timing_out->v_front_porch = mode_in->vsync_start - mode_in->vdisplay;
> +		timing_out->v_sync_width = mode_in->vsync_end - mode_in->vsync_start;
> +		timing_out->pix_clk_100hz = mode_in->clock * 10;
> +	} else {
> +		timing_out->h_addressable = mode_in->crtc_hdisplay;
> +		timing_out->h_total = mode_in->crtc_htotal;
> +		timing_out->h_sync_width = mode_in->crtc_hsync_end - mode_in->crtc_hsync_start;
> +		timing_out->h_front_porch = mode_in->crtc_hsync_start - mode_in->crtc_hdisplay;
> +		timing_out->v_total = mode_in->crtc_vtotal;
> +		timing_out->v_addressable = mode_in->crtc_vdisplay;
> +		timing_out->v_front_porch = mode_in->crtc_vsync_start - mode_in->crtc_vdisplay;
> +		timing_out->v_sync_width = mode_in->crtc_vsync_end - mode_in->crtc_vsync_start;
> +		timing_out->pix_clk_100hz = mode_in->crtc_clock * 10;
> +	}
> +
>  	timing_out->aspect_ratio = get_aspect_ratio(mode_in);
>  
>  	stream->output_color_space = get_output_color_space(timing_out);
> @@ -5227,6 +5240,24 @@ get_highest_refresh_rate_mode(struct amdgpu_dm_connector *aconnector,
>  	return m_pref;
>  }
>  
> +static bool is_freesync_video_mode(struct drm_display_mode *mode,
> +				   struct amdgpu_dm_connector *aconnector)
> +{
> +	struct drm_display_mode *high_mode;
> +
> +	high_mode = get_highest_refresh_rate_mode(aconnector, false);
> +	if (!high_mode || !mode)
> +		return false;
> +
> +	if (high_mode->clock == 0 ||
> +	    high_mode->hdisplay != mode->hdisplay ||
> +	    high_mode->vdisplay != mode->vdisplay ||
> +	    high_mode->clock != mode->clock)
> +		return false;
> +	else
> +		return true;
> +}
> +
>  static struct dc_stream_state *
>  create_stream_for_sink(struct amdgpu_dm_connector *aconnector,
>  		       const struct drm_display_mode *drm_mode,
> @@ -5240,15 +5271,21 @@ create_stream_for_sink(struct amdgpu_dm_connector *aconnector,
>  		dm_state ? &dm_state->base : NULL;
>  	struct dc_stream_state *stream = NULL;
>  	struct drm_display_mode mode = *drm_mode;
> +	struct drm_display_mode saved_mode;
> +	struct drm_display_mode *freesync_mode = NULL;
>  	bool native_mode_found = false;
>  	bool scale = dm_state ? (dm_state->scaling != RMX_OFF) : false;
>  	int mode_refresh;
>  	int preferred_refresh = 0;
> +	bool is_fs_vid_mode = 0;
>  #if defined(CONFIG_DRM_AMD_DC_DCN)
>  	struct dsc_dec_dpcd_caps dsc_caps;
>  	uint32_t link_bandwidth_kbps;
>  #endif
>  	struct dc_sink *sink = NULL;
> +
> +	memset(&saved_mode, 0, sizeof(struct drm_display_mode));
> +
>  	if (aconnector == NULL) {
>  		DRM_ERROR("aconnector is NULL!\n");
>  		return stream;
> @@ -5301,25 +5338,39 @@ create_stream_for_sink(struct amdgpu_dm_connector *aconnector,
>  		 */
>  		DRM_DEBUG_DRIVER("No preferred mode found\n");
>  	} else {
> -		decide_crtc_timing_for_drm_display_mode(
> +		is_fs_vid_mode = is_freesync_video_mode(&mode, aconnector);
> +		if (is_fs_vid_mode) {
> +			freesync_mode = get_highest_refresh_rate_mode(aconnector, false);
> +			saved_mode = mode;
> +			mode = *freesync_mode;
> +		}
> +
> +		if (!is_fs_vid_mode)
This should go as else {} case for above if() instead of a new check
> +			decide_crtc_timing_for_drm_display_mode(
>  				&mode, preferred_mode,
>  				dm_state ? (dm_state->scaling != RMX_OFF) : false);
> +
>  		preferred_refresh = drm_mode_vrefresh(preferred_mode);
>  	}
>  
>  	if (!dm_state)
>  		drm_mode_set_crtcinfo(&mode, 0);
>  
> -	/*
> +	if (dm_state && is_fs_vid_mode)
> +		drm_mode_set_crtcinfo(&saved_mode, 0);
Why is this step required ?
> +
> +       /*
>  	* If scaling is enabled and refresh rate didn't change
>  	* we copy the vic and polarities of the old timings
>  	*/
> -	if (!scale || mode_refresh != preferred_refresh)
> -		fill_stream_properties_from_drm_display_mode(stream,
> -			&mode, &aconnector->base, con_state, NULL, requested_bpc);
> +	if (!(scale && is_fs_vid_mode) || mode_refresh != preferred_refresh)
> +		fill_stream_properties_from_drm_display_mode(
> +			stream, &mode, &aconnector->base, con_state, NULL,
> +			requested_bpc, dm_state ? 1 : 0);
>  	else
> -		fill_stream_properties_from_drm_display_mode(stream,
> -			&mode, &aconnector->base, con_state, old_stream, requested_bpc);
> +		fill_stream_properties_from_drm_display_mode(
> +			stream, &mode, &aconnector->base, con_state, old_stream,
> +			requested_bpc, dm_state ? 1 : 0);
>  
>  	stream->timing.flags.DSC = 0;
>  
> @@ -7844,13 +7895,29 @@ static void update_stream_irq_parameters(
>  	if (new_crtc_state->vrr_supported &&
>  	    config.min_refresh_in_uhz &&
>  	    config.max_refresh_in_uhz) {
> +		/*
> +		 * if freesync compatible mode was set, config.state will be set
> +		 * in atomic check
> +		 */
> +		if (config.state == VRR_STATE_ACTIVE_FIXED &&
> +		    config.fixed_refresh_in_uhz && config.max_refresh_in_uhz &&
> +		    config.min_refresh_in_uhz &&
> +		    (!drm_atomic_crtc_needs_modeset(&new_crtc_state->base) ||
> +		     new_crtc_state->freesync_video_mode)) {
> +			vrr_params.max_refresh_in_uhz = config.max_refresh_in_uhz;
> +			vrr_params.min_refresh_in_uhz = config.min_refresh_in_uhz;
> +			vrr_params.fixed_refresh_in_uhz = config.fixed_refresh_in_uhz;
> +			vrr_params.state = VRR_STATE_ACTIVE_FIXED;
> +			goto out;
> +		}
> +
>  		config.state = new_crtc_state->base.vrr_enabled ?
>  			VRR_STATE_ACTIVE_VARIABLE :
>  			VRR_STATE_INACTIVE;
> -	} else {
> +	} else
conventionally, if a if() condition has {}, its else condition should also have {}, even if it's a single statement. So you can skip this change.
>  		config.state = VRR_STATE_UNSUPPORTED;
> -	}
>  
> +out:
>  	mod_freesync_build_vrr_params(dm->freesync_module,
>  				      new_stream,
>  				      &config, &vrr_params);
> @@ -8168,7 +8235,9 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
>  		 * as part of commit.
>  		 */
>  		if (amdgpu_dm_vrr_active(dm_old_crtc_state) !=
> -		    amdgpu_dm_vrr_active(acrtc_state)) {
> +		    amdgpu_dm_vrr_active(acrtc_state) ||
> +		    acrtc_state->freesync_config.state == VRR_STATE_ACTIVE_FIXED ||
> +		    acrtc_state->freesync_video_mode) {
>  			spin_lock_irqsave(&pcrtc->dev->event_lock, flags);
>  			dc_stream_adjust_vmin_vmax(
>  				dm->dc, acrtc_state->stream,
> @@ -8864,6 +8933,7 @@ static void get_freesync_config_for_crtc(
>  			to_amdgpu_dm_connector(new_con_state->base.connector);
>  	struct drm_display_mode *mode = &new_crtc_state->base.mode;
>  	int vrefresh = drm_mode_vrefresh(mode);
> +	bool fs_vid_mode = false;
>  
>  	new_crtc_state->vrr_supported = new_con_state->freesync_capable &&
>  					vrefresh >= aconnector->min_vfreq &&
> @@ -8871,17 +8941,26 @@ static void get_freesync_config_for_crtc(
>  
>  	if (new_crtc_state->vrr_supported) {
>  		new_crtc_state->stream->ignore_msa_timing_param = true;
> -		config.state = new_crtc_state->base.vrr_enabled ?
> -				VRR_STATE_ACTIVE_VARIABLE :
> -				VRR_STATE_INACTIVE;
> -		config.min_refresh_in_uhz =
> -				aconnector->min_vfreq * 1000000;
> -		config.max_refresh_in_uhz =
> -				aconnector->max_vfreq * 1000000;
> +		fs_vid_mode = new_crtc_state->freesync_config.state == VRR_STATE_ACTIVE_FIXED ||
> +			new_crtc_state->freesync_video_mode;
> +
> +		config.min_refresh_in_uhz = aconnector->min_vfreq * 1000000;
> +		config.max_refresh_in_uhz = aconnector->max_vfreq * 1000000;
>  		config.vsif_supported = true;
>  		config.btr = true;
> -	}
>  
> +		if (fs_vid_mode) {
> +			config.state = VRR_STATE_ACTIVE_FIXED;
> +			config.fixed_refresh_in_uhz = new_crtc_state->freesync_config.fixed_refresh_in_uhz;
> +			goto out;
> +		}
> +		else if (new_crtc_state->base.vrr_enabled && !fs_vid_mode)
> +			config.state = VRR_STATE_ACTIVE_VARIABLE;
> +		else
> +			config.state = VRR_STATE_INACTIVE;
> +
> +	}
> +out:
>  	new_crtc_state->freesync_config = config;
>  }
>  
> @@ -8894,6 +8973,51 @@ static void reset_freesync_config_for_crtc(
>  	       sizeof(new_crtc_state->vrr_infopacket));
>  }
>  
> +static bool
> +is_timing_unchanged_for_freesync(struct drm_crtc_state *old_crtc_state,
> +				 struct drm_crtc_state *new_crtc_state)
> +{
> +	struct drm_display_mode old_mode, new_mode;
> +
> +	if (!old_crtc_state || !new_crtc_state)
> +		return false;
> +
> +	old_mode = old_crtc_state->mode;
> +	new_mode = new_crtc_state->mode;
> +
> +	if (old_mode.clock       == new_mode.clock &&
> +	    old_mode.hdisplay    == new_mode.hdisplay &&
> +	    old_mode.vdisplay    == new_mode.vdisplay &&
> +	    old_mode.htotal      == new_mode.htotal &&
> +	    old_mode.vtotal      != new_mode.vtotal &&
> +	    old_mode.hsync_start == new_mode.hsync_start &&
> +	    old_mode.vsync_start != new_mode.vsync_start &&
> +	    old_mode.hsync_end   == new_mode.hsync_end &&
> +	    old_mode.vsync_end   != new_mode.vsync_end &&
> +	    old_mode.hskew       == new_mode.hskew &&
> +	    old_mode.vscan       == new_mode.vscan &&
> +	    (old_mode.vsync_end - old_mode.vsync_start) ==
> +	    (new_mode.vsync_end - new_mode.vsync_start))
> +		return true;
> +
> +	return false;
> +}
> +
> +static void set_freesync_fixed_config(struct dm_crtc_state *dm_new_crtc_state) {
> +	uint64_t num, den, res;
> +	struct drm_crtc_state *new_crtc_state = &dm_new_crtc_state->base;
> +
> +	dm_new_crtc_state->freesync_config.state = VRR_STATE_ACTIVE_FIXED;
> +
> +	num = (unsigned long long)new_crtc_state->mode.clock * 1000 * 1000000;
> +	den = (unsigned long long)new_crtc_state->mode.htotal *
> +	      (unsigned long long)new_crtc_state->mode.vtotal;
> +
> +	res = div_u64(num, den);
> +	dm_new_crtc_state->freesync_config.fixed_refresh_in_uhz = res;
> +	dm_new_crtc_state->freesync_video_mode = true;
> +}
> +
>  static int dm_update_crtc_state(struct amdgpu_display_manager *dm,
>  				struct drm_atomic_state *state,
>  				struct drm_crtc *crtc,
> @@ -8984,6 +9108,11 @@ static int dm_update_crtc_state(struct amdgpu_display_manager *dm,
>  		 * TODO: Refactor this function to allow this check to work
>  		 * in all conditions.
>  		 */
> +		if (dm_new_crtc_state->stream &&
> +		    is_timing_unchanged_for_freesync(new_crtc_state, old_crtc_state) &&
> +		    amdgpu_exp_freesync_vid_mode)
keeping this flag check before the function call might allow the compiler to save the function call, when this flag is disabled. 
> +			goto skip_modeset;
> +
>  		if (dm_new_crtc_state->stream &&
>  		    dc_is_stream_unchanged(new_stream, dm_old_crtc_state->stream) &&
>  		    dc_is_stream_scaling_unchanged(new_stream, dm_old_crtc_state->stream)) {
> @@ -9015,6 +9144,23 @@ static int dm_update_crtc_state(struct amdgpu_display_manager *dm,
>  		if (!dm_old_crtc_state->stream)
>  			goto skip_modeset;
>  
> +		if (dm_new_crtc_state->stream &&
> +		    is_timing_unchanged_for_freesync(new_crtc_state, old_crtc_state) &&
> +		    amdgpu_exp_freesync_vid_mode) {
same here
> +			new_crtc_state->mode_changed = false;
> +			DRM_DEBUG_DRIVER(
> +				"Mode change not required for front porch change, "
> +				"setting mode_changed to %d",
> +				new_crtc_state->mode_changed);
> +
> +			set_freesync_fixed_config(dm_new_crtc_state);
> +
> +			goto skip_modeset;
> +		} else if (aconnector &&
> +			   is_freesync_video_mode(&new_crtc_state->mode, aconnector) &&
> +			   amdgpu_exp_freesync_vid_mode)
> +			set_freesync_fixed_config(dm_new_crtc_state);
> +
>  		ret = dm_atomic_get_state(state, &dm_state);
>  		if (ret)
>  			goto fail;
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> index f5a5f1ad7dba..fd5fb9dafded 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
> @@ -455,6 +455,7 @@ struct dm_crtc_state {
>  
>  	bool freesync_timing_changed;
>  	bool freesync_vrr_info_changed;
> +	bool freesync_video_mode;
>  
>  	bool dsc_force_changed;
>  	bool vrr_supported;

With the minor comments fixed/explained above,

this patch is Reviewed-by: Shashank Sharma <shashank.sharma at amd.com>

- Shashank



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