[PATCH] drm/i915/display: use port not transcoder for PORT_ALPM_CTL

[Kaushlendra Kumar <kaushlendra.kumar@intel.com>]

intel_alpm_disable() incorrectly passes cpu_transcoder as the
index to PORT_ALPM_CTL(), which expects an enum port. This
writes to the wrong register, potentially corrupting state on
unrelated ports.

Use dp_to_dig_port(intel_dp)->base.port to access the correct
port-indexed register.

Signed-off-by: Kaushlendra Kumar <kaushlendra.kumar@intel.com>
---
 drivers/gpu/drm/i915/display/intel_alpm.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_alpm.c b/drivers/gpu/drm/i915/display/intel_alpm.c
index 6372f533f65b..09ba1c2be16c 100644
--- a/drivers/gpu/drm/i915/display/intel_alpm.c
+++ b/drivers/gpu/drm/i915/display/intel_alpm.c
@@ -557,6 +557,7 @@ void intel_alpm_disable(struct intel_dp *intel_dp)
 {
 	struct intel_display *display = to_intel_display(intel_dp);
 	enum transcoder cpu_transcoder = intel_dp->alpm.transcoder;
+	enum port port = dp_to_dig_port(intel_dp)->base.port;
 
 	if (DISPLAY_VER(display) < 20 || !intel_dp->alpm_dpcd)
 		return;
@@ -568,7 +569,7 @@ void intel_alpm_disable(struct intel_dp *intel_dp)
 		     ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
 
 	intel_de_rmw(display,
-		     PORT_ALPM_CTL(cpu_transcoder),
+		     PORT_ALPM_CTL(port),
 		     PORT_ALPM_CTL_ALPM_AUX_LESS_ENABLE, 0);
 
 	drm_dbg_kms(display->drm, "Disabling ALPM\n");
-- 
2.34.1