Commit f57fa0f2 authored by Leo Chen's avatar Leo Chen Committed by Alex Deucher
Browse files

drm/amd/display: Add symclk workaround during disable link output 



[Why & How]
This is originally a change (9c75891f) in DCN32 because of the lack
of interface to set TX while keeping symclk on. Adding this workaround
to DCN314 will resolve the current issue.

Fixes: 9c75891f ("drm/amd/display: rework recent update PHY state commit")
Reviewed-by: default avatarNicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: default avatarAlex Hung <alex.hung@amd.com>
Signed-off-by: default avatarLeo Chen <sancchen@amd.com>
Tested-by: default avatarDaniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent 58d9b9a1

drivers/gpu/drm/amd/display/dc/dcn314/dcn314_hwseq.c

+65 −0
Original line number Diff line number Diff line
@@ -423,3 +423,68 @@ void dcn314_hubp_pg_control(struct dce_hwseq *hws, unsigned int hubp_inst, bool 


	PERF_TRACE();

}

static void apply_symclk_on_tx_off_wa(struct dc_link *link)

{

	/* There are use cases where SYMCLK is referenced by OTG. For instance

	 * for TMDS signal, OTG relies SYMCLK even if TX video output is off.

	 * However current link interface will power off PHY when disabling link

	 * output. This will turn off SYMCLK generated by PHY. The workaround is

	 * to identify such case where SYMCLK is still in use by OTG when we

	 * power off PHY. When this is detected, we will temporarily power PHY

	 * back on and move PHY's SYMCLK state to SYMCLK_ON_TX_OFF by calling

	 * program_pix_clk interface. When OTG is disabled, we will then power

	 * off PHY by calling disable link output again.

	 *

	 * In future dcn generations, we plan to rework transmitter control

	 * interface so that we could have an option to set SYMCLK ON TX OFF

	 * state in one step without this workaround

	 */



	struct dc *dc = link->ctx->dc;

	struct pipe_ctx *pipe_ctx = NULL;

	uint8_t i;



	if (link->phy_state.symclk_ref_cnts.otg > 0) {

		for (i = 0; i < MAX_PIPES; i++) {

			pipe_ctx = &dc->current_state->res_ctx.pipe_ctx[i];

			if (pipe_ctx->stream && pipe_ctx->stream->link == link && pipe_ctx->top_pipe == NULL) {

				pipe_ctx->clock_source->funcs->program_pix_clk(

						pipe_ctx->clock_source,

						&pipe_ctx->stream_res.pix_clk_params,

						dc->link_srv->dp_get_encoding_format(

								&pipe_ctx->link_config.dp_link_settings),

						&pipe_ctx->pll_settings);

				link->phy_state.symclk_state = SYMCLK_ON_TX_OFF;

				break;

			}

		}

	}

}



void dcn314_disable_link_output(struct dc_link *link,

		const struct link_resource *link_res,

		enum signal_type signal)

{

	struct dc *dc = link->ctx->dc;

	const struct link_hwss *link_hwss = get_link_hwss(link, link_res);

	struct dmcu *dmcu = dc->res_pool->dmcu;



	if (signal == SIGNAL_TYPE_EDP &&

			link->dc->hwss.edp_backlight_control)

		link->dc->hwss.edp_backlight_control(link, false);

	else if (dmcu != NULL && dmcu->funcs->lock_phy)

		dmcu->funcs->lock_phy(dmcu);



	link_hwss->disable_link_output(link, link_res, signal);

	link->phy_state.symclk_state = SYMCLK_OFF_TX_OFF;

	/*

	 * Add the logic to extract BOTH power up and power down sequences

	 * from enable/disable link output and only call edp panel control

	 * in enable_link_dp and disable_link_dp once.

	 */

	if (dmcu != NULL && dmcu->funcs->lock_phy)

		dmcu->funcs->unlock_phy(dmcu);

	dc->link_srv->dp_trace_source_sequence(link, DPCD_SOURCE_SEQ_AFTER_DISABLE_LINK_PHY);



	apply_symclk_on_tx_off_wa(link);

}

drivers/gpu/drm/amd/display/dc/dcn314/dcn314_hwseq.h

+2 −0
Original line number Diff line number Diff line
@@ -45,4 +45,6 @@ void dcn314_hubp_pg_control(struct dce_hwseq *hws, unsigned int hubp_inst, bool 


void dcn314_dpp_root_clock_control(struct dce_hwseq *hws, unsigned int dpp_inst, bool clock_on);



void dcn314_disable_link_output(struct dc_link *link, const struct link_resource *link_res, enum signal_type signal);



#endif /* __DC_HWSS_DCN314_H__ */

drivers/gpu/drm/amd/display/dc/dcn314/dcn314_init.c

+1 −1
Original line number Diff line number Diff line
@@ -105,7 +105,7 @@ static const struct hw_sequencer_funcs dcn314_funcs = { 
	.enable_lvds_link_output = dce110_enable_lvds_link_output,

	.enable_tmds_link_output = dce110_enable_tmds_link_output,

	.enable_dp_link_output = dce110_enable_dp_link_output,

	.disable_link_output = dce110_disable_link_output,

	.disable_link_output = dcn314_disable_link_output,

	.z10_restore = dcn31_z10_restore,

	.z10_save_init = dcn31_z10_save_init,

	.set_disp_pattern_generator = dcn30_set_disp_pattern_generator,