[PATCH] drm/i915/dp_mst: Fix disabling the minimum HBlank time

[Imre Deak]

Disable the minimum HBlank time only on LNL+, where this functionality
and corresponding register exists.

Fixes: a5ebe00c2ace ("drm/i915/dp: Guarantee a minimum HBlank time")
Cc: Arun R Murthy <arun.r.murthy at intel.com>
Cc: Suraj Kandpal <suraj.kandpal at intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp_mst.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index ae2db983eff92..459440dd6e879 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -1006,7 +1006,8 @@ static void mst_stream_disable(struct intel_atomic_state *state,
 
 	intel_dp_sink_disable_decompression(state, connector, old_crtc_state);
 
-	intel_de_write(display, DP_MIN_HBLANK_CTL(trans), 0x00);
+	if (DISPLAY_VER(display) >= 20)
+		intel_de_write(display, DP_MIN_HBLANK_CTL(trans), 0);
 }
 
 static void mst_stream_post_disable(struct intel_atomic_state *state,
-- 
2.44.2