drm/i915/bxt: WA for swapped HPD pins in A stepping

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)
v5: Don’t check for PORT_A in intel_ddi_init to update dig_port,
instead avoid setting hpd_pin itself (Imre)

Signed-off-by: Sonika Jindal <sonika.jindal@intel.com>
Reviewed-by: Sivakumar Thulasimani <sivakumar.thulasimani@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 8 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 51cbea8247fe..0cfbe85fe271 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))