drm/i915: Init lspcon after HPD in intel_dp_detect()

On HP 800 G4 DM, if HDMI cable isn't plugged before boot, the HDMI port
becomes useless and never responds to cable hotplugging:
[    3.031904] [drm:lspcon_init [i915]] *ERROR* Failed to probe lspcon
[    3.031945] [drm:intel_ddi_init [i915]] *ERROR* LSPCON init failed on port D

Seems like the lspcon chip on the system only gets powered after the
cable is plugged.

Consilidate lspcon_init() into lspcon_resume() to dynamically init
lspcon chip, and make HDMI port work.

v6:
 - Rebase on latest for-linux-next.
v5:
 - Consolidate lspcon_resume() with lspcon_init().
 - Move more logic into lspcon code.
v4:
 - Trust VBT in intel_infoframe_init().
 - Init lspcon in intel_dp_detect().
v3:
 - Make sure it's handled under long HPD case.
v2:
 - Move lspcon_init() inside of intel_dp_hpd_pulse().

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/203
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200610075542.12882-1-kai.heng.feng@canonical.com

1 files changed, 1 insertions, 18 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 5742394c8292..b4c520348b3b 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -5111,7 +5111,7 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 {
 	struct intel_digital_port *dig_port;
 	struct intel_encoder *encoder;
-	bool init_hdmi, init_dp, init_lspcon = false;
+	bool init_hdmi, init_dp;
 	enum phy phy = intel_port_to_phy(dev_priv, port);
 
 	/*
@@ -5137,7 +5137,6 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 		 * is initialized before lspcon.
 		 */
 		init_dp = true;
-		init_lspcon = true;
 		init_hdmi = false;
 		drm_dbg_kms(&dev_priv->drm, "VBT says port %c has lspcon\n",
 			    port_name(port));
@@ -5238,22 +5237,6 @@ void intel_ddi_init(struct drm_i915_private *dev_priv, enum port port)
 			goto err;
 	}
 
-	if (init_lspcon) {
-		if (lspcon_init(dig_port))
-			/* TODO: handle hdmi info frame part */
-			drm_dbg_kms(&dev_priv->drm,
-				    "LSPCON init success on port %c\n",
-				    port_name(port));
-		else
-			/*
-			 * LSPCON init faied, but DP init was success, so
-			 * lets try to drive as DP++ port.
-			 */
-			drm_err(&dev_priv->drm,
-				"LSPCON init failed on port %c\n",
-				port_name(port));
-	}
-
 	if (INTEL_GEN(dev_priv) >= 11) {
 		if (intel_phy_is_tc(dev_priv, phy))
 			dig_port->connected = intel_tc_port_connected;