[PATCH v3] drm/i915: protect access to DP_TP_* on non-dp

[Lucas De Marchi]

DP_TP_{CTL,STATUS} should only be programmed when the encoder is intel_dp.
Checking its current usages intel_disable_ddi_buf() is the only
offender, with other places being protected by checks like
pipe_config->fec_enable that is only set by intel_dp.

Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Signed-off-by: Lucas De Marchi <lucas.demarchi at intel.com>
---
 drivers/gpu/drm/i915/display/intel_ddi.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index 3180dacb5be4..df3e4fe7e3e9 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -3462,10 +3462,12 @@ static void intel_disable_ddi_buf(struct intel_encoder *encoder,
 		wait = true;
 	}
 
-	val = I915_READ(DP_TP_CTL(port));
-	val &= ~(DP_TP_CTL_ENABLE | DP_TP_CTL_LINK_TRAIN_MASK);
-	val |= DP_TP_CTL_LINK_TRAIN_PAT1;
-	I915_WRITE(DP_TP_CTL(port), val);
+	if (intel_encoder_is_dp(encoder)) {
+		val = I915_READ(DP_TP_CTL(port));
+		val &= ~(DP_TP_CTL_ENABLE | DP_TP_CTL_LINK_TRAIN_MASK);
+		val |= DP_TP_CTL_LINK_TRAIN_PAT1;
+		I915_WRITE(DP_TP_CTL(port), val);
+	}
 
 	/* Disable FEC in DP Sink */
 	intel_ddi_disable_fec_state(encoder, crtc_state);
-- 
2.23.0