[Intel-gfx] [PATCH] drm/i915: Protect against wrong reg offset and warn.

[Rodrigo Vivi]

In case we forget to change intel_port_is_tc
we would be trying to access registers with port == -1,
i.e. PORT_TC_NONE, what would be wrong offset.

So let's just add a protection and warn here.

Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 436c22de33b6..6a93fa9bbbd9 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4886,6 +4886,9 @@ static bool icl_tc_port_connected(struct drm_i915_private *dev_priv,
 	bool is_legacy, is_typec, is_tbt;
 	u32 dpsp;
 
+	if (WARN_ON(tc_port == PORT_TC_NONE))
+		return false;
+
 	is_legacy = I915_READ(SDEISR) & SDE_TC_HOTPLUG_ICP(tc_port);
 
 	/*
-- 
2.17.1