From: Leo Chen <sancchen@xxxxxxx>
[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: 9c75891feef0 ("drm/amd/display: rework recent update PHY state commit")
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@xxxxxxx>
Acked-by: Alex Hung <alex.hung@xxxxxxx>
Signed-off-by: Leo Chen <sancchen@xxxxxxx>
---
.../drm/amd/display/dc/dcn314/dcn314_hwseq.c | 65 +++++++++++++++++++
.../drm/amd/display/dc/dcn314/dcn314_hwseq.h | 2 +
.../drm/amd/display/dc/dcn314/dcn314_init.c | 2 +-
3 files changed, 68 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_hwseq.c
index 6fb3f64e3057..f7a3e0d71d01 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_hwseq.c
@@ -421,3 +421,68 @@ 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);
+}
diff --git a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_hwseq.h b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_hwseq.h
index c786d5e6a428..6d0b62503caa 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_hwseq.h
+++ b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_hwseq.h
@@ -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__ */
diff --git a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_init.c b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_init.c
index ce53339b2e10..ed8a1b94c006 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_init.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn314/dcn314_init.c
@@ -106,7 +106,7 @@ 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,
--
2.40.0
