[Intel-gfx] [PATCH] drm/i915/bxt: WA for swapped HPD pins in A stepping

[Sonika Jindal]

WA for BXT A0/A1, where DDIB's HPD pin is swapped to DDIA, so enabling
DDIA HPD pin in place of DDIB.

v2: For DP, irq_port is used to determine the encoder instead of
hpd_pin and removing the edp HPD logic because port A HPD is not
present(Imre)
v3: Rebased on top of Imre's patchset for enabling HPD on PORT A.
Added hpd_pin swapping for intel_dp_init_connector, setting encoder
for PORT_A as per the WA in irq_port (Imre)
v4: Dont enable interrupt for edp, also reframe the description (Siva)

Signed-off-by: Sonika Jindal <sonika.jindal at intel.com>
---
 drivers/gpu/drm/i915/intel_ddi.c  |   11 ++++++++++-
 drivers/gpu/drm/i915/intel_dp.c   |    4 ++++
 drivers/gpu/drm/i915/intel_hdmi.c |    9 ++++++++-
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index e2c6f73..8d7ffe0 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -3225,7 +3225,16 @@ void intel_ddi_init(struct drm_device *dev, enum port port)
 			goto err;
 
 		intel_dig_port->hpd_pulse = intel_dp_hpd_pulse;
-		dev_priv->hotplug.irq_port[port] = intel_dig_port;
+		/*
+		 * On BXT A0/A1, sw needs to activate DDIA HPD logic and
+		 * interrupts to check the external panel connection.
+		 */
+		if (IS_BROXTON(dev_priv) && (INTEL_REVID(dev) < BXT_REVID_B0)
+					 && port == PORT_B)
+			dev_priv->hotplug.irq_port[PORT_A] = intel_dig_port;
+		/* Dont enable interrupts for edp*/
+		else if (port != PORT_A)
+			dev_priv->hotplug.irq_port[port] = intel_dig_port;
 	}
 
 	/* In theory we don't need the encoder->type check, but leave it just in
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index fcc64e5..71679ef 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -5785,9 +5785,13 @@ intel_dp_init_connector(struct intel_digital_port *intel_dig_port,
 	switch (port) {
 	case PORT_A:
 		intel_encoder->hpd_pin = HPD_PORT_A;
+		if (IS_BROXTON(dev_priv) && (INTEL_REVID(dev) < BXT_REVID_B0))
+			intel_encoder->hpd_pin = HPD_PORT_C;
 		break;
 	case PORT_B:
 		intel_encoder->hpd_pin = HPD_PORT_B;
+		if (IS_BROXTON(dev_priv) && (INTEL_REVID(dev) < BXT_REVID_B0))
+			intel_encoder->hpd_pin = HPD_PORT_A;
 		break;
 	case PORT_C:
 		intel_encoder->hpd_pin = HPD_PORT_C;
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 70bad5b..94fa716 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1973,7 +1973,14 @@ void intel_hdmi_init_connector(struct intel_digital_port *intel_dig_port,
 			intel_hdmi->ddc_bus = GMBUS_PIN_1_BXT;
 		else
 			intel_hdmi->ddc_bus = GMBUS_PIN_DPB;
-		intel_encoder->hpd_pin = HPD_PORT_B;
+		/*
+		 * On BXT A0/A1, sw needs to activate DDIA HPD logic and
+		 * interrupts to check the external panel connection.
+		 */
+		if (IS_BROXTON(dev_priv) && (INTEL_REVID(dev) < BXT_REVID_B0))
+			intel_encoder->hpd_pin = HPD_PORT_A;
+		else
+			intel_encoder->hpd_pin = HPD_PORT_B;
 		break;
 	case PORT_C:
 		if (IS_BROXTON(dev_priv))
-- 
1.7.10.4