From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
I want intel_dp->DP to be fully populated by the time the
initial vswing programming happens. To that end move the
intel_ddi_init_dp_buf_reg() call to an earlier spot.
Additionally we don't want intel_ddi_init_dp_buf_reg() to
set DDI_BUF_CTL_ENABLE since the port should only get enabled
at the start of link training (see intel_ddi_prepare_link_retrain()).
So any earlier write to the register should not set the enable bit.
Cc: Imre Deak <imre.deak@xxxxxxxxx>
Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_ddi.c | 44 +++++++++++-------------
1 file changed, 21 insertions(+), 23 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 51d07e9af9f3..65e59f16879d 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -282,9 +282,10 @@ static void intel_ddi_init_dp_buf_reg(struct intel_encoder *encoder,
struct intel_digital_port *dig_port = enc_to_dig_port(encoder);
enum phy phy = intel_port_to_phy(i915, encoder->port);
+ /* DDI_BUF_CTL_ENABLE will be set by intel_ddi_prepare_link_retrain() later */
intel_dp->DP = dig_port->saved_port_bits |
- DDI_BUF_CTL_ENABLE | DDI_BUF_TRANS_SELECT(0);
- intel_dp->DP |= DDI_PORT_WIDTH(crtc_state->lane_count);
+ DDI_PORT_WIDTH(crtc_state->lane_count) |
+ DDI_BUF_TRANS_SELECT(0);
if (IS_ALDERLAKE_P(i915) && intel_phy_is_tc(i915, phy)) {
intel_dp->DP |= ddi_buf_phy_link_rate(crtc_state->port_clock);
@@ -2360,6 +2361,12 @@ static void dg2_ddi_pre_enable_dp(struct intel_atomic_state *state,
intel_dp_set_link_params(intel_dp, crtc_state->port_clock,
crtc_state->lane_count);
+ /*
+ * We only configure what the register value will be here. Actual
+ * enabling happens during link training farther down.
+ */
+ intel_ddi_init_dp_buf_reg(encoder, crtc_state);
+
/*
* 1. Enable Power Wells
*
@@ -2416,16 +2423,6 @@ static void dg2_ddi_pre_enable_dp(struct intel_atomic_state *state,
/* 5.e Configure voltage swing and related IO settings */
intel_snps_phy_ddi_vswing_sequence(encoder, crtc_state, level);
- /*
- * 5.f Configure and enable DDI_BUF_CTL
- * 5.g Wait for DDI_BUF_CTL DDI Idle Status = 0b (Not Idle), timeout
- * after 1200 us.
- *
- * We only configure what the register value will be here. Actual
- * enabling happens during link training farther down.
- */
- intel_ddi_init_dp_buf_reg(encoder, crtc_state);
-
if (!is_mst)
intel_dp_set_power(intel_dp, DP_SET_POWER_D0);
@@ -2473,6 +2470,12 @@ static void tgl_ddi_pre_enable_dp(struct intel_atomic_state *state,
crtc_state->port_clock,
crtc_state->lane_count);
+ /*
+ * We only configure what the register value will be here. Actual
+ * enabling happens during link training farther down.
+ */
+ intel_ddi_init_dp_buf_reg(encoder, crtc_state);
+
/*
* 1. Enable Power Wells
*
@@ -2554,16 +2557,6 @@ static void tgl_ddi_pre_enable_dp(struct intel_atomic_state *state,
*/
intel_ddi_mso_configure(crtc_state);
- /*
- * 7.g Configure and enable DDI_BUF_CTL
- * 7.h Wait for DDI_BUF_CTL DDI Idle Status = 0b (Not Idle), timeout
- * after 500 us.
- *
- * We only configure what the register value will be here. Actual
- * enabling happens during link training farther down.
- */
- intel_ddi_init_dp_buf_reg(encoder, crtc_state);
-
if (!is_mst)
intel_dp_set_power(intel_dp, DP_SET_POWER_D0);
@@ -2620,6 +2613,12 @@ static void hsw_ddi_pre_enable_dp(struct intel_atomic_state *state,
crtc_state->port_clock,
crtc_state->lane_count);
+ /*
+ * We only configure what the register value will be here. Actual
+ * enabling happens during link training farther down.
+ */
+ intel_ddi_init_dp_buf_reg(encoder, crtc_state);
+
intel_pps_on(intel_dp);
intel_ddi_enable_clock(encoder, crtc_state);
@@ -2641,7 +2640,6 @@ static void hsw_ddi_pre_enable_dp(struct intel_atomic_state *state,
intel_ddi_power_up_lanes(encoder, crtc_state);
- intel_ddi_init_dp_buf_reg(encoder, crtc_state);
if (!is_mst)
intel_dp_set_power(intel_dp, DP_SET_POWER_D0);
intel_dp_configure_protocol_converter(intel_dp, crtc_state);
--
2.32.0
