[Intel-gfx] [PATCH] drm/i915/display: Only query DP state of a DDI encoder

[Chris Wilson]

Avoid a NULL dereference for a mismatched encoder type, hit when
probing state for all encoders.

Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1892
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 1768731678a1..4749d2fe2324 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5212,6 +5212,9 @@ void intel_read_dp_sdp(struct intel_encoder *encoder,
 		       struct intel_crtc_state *crtc_state,
 		       unsigned int type)
 {
+	if (encoder->type != INTEL_OUTPUT_DDI)
+		return;
+
 	switch (type) {
 	case DP_SDP_VSC:
 		intel_read_dp_vsc_sdp(encoder, crtc_state,
-- 
2.20.1