drm/i915/icl: fix icl_unmap/map_plls_to_ports

All connectors may not have best_encoder attached, so don't dereference
encoder pointer for each connector.

Fixes: c27e917e2bda ("drm/i915/icl: add basic support for the ICL clocks")
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Mahesh Kumar <mahesh1.kumar@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180525155238.7054-1-lucas.demarchi@intel.com
(cherry picked from commit c46ef57d2008e5195f086a538550488b49644db7)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index b98ac05..f4a8598 100644 (file)
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -2453,12 +2453,13 @@ void icl_map_plls_to_ports(struct drm_crtc *crtc,
        for_each_new_connector_in_state(old_state, conn, conn_state, i) {
                struct intel_encoder *encoder =
                        to_intel_encoder(conn_state->best_encoder);
-               enum port port = encoder->port;
+               enum port port;
                uint32_t val;
 
                if (conn_state->crtc != crtc)
                        continue;
 
+               port = encoder->port;
                mutex_lock(&dev_priv->dpll_lock);
 
                val = I915_READ(DPCLKA_CFGCR0_ICL);
@@ -2490,11 +2491,12 @@ void icl_unmap_plls_to_ports(struct drm_crtc *crtc,
        for_each_old_connector_in_state(old_state, conn, old_conn_state, i) {
                struct intel_encoder *encoder =
                        to_intel_encoder(old_conn_state->best_encoder);
-               enum port port = encoder->port;
+               enum port port;
 
                if (old_conn_state->crtc != crtc)
                        continue;
 
+               port = encoder->port;
                mutex_lock(&dev_priv->dpll_lock);
                I915_WRITE(DPCLKA_CFGCR0_ICL,
                           I915_READ(DPCLKA_CFGCR0_ICL) |