drm: always determine branch device with drm_dp_is_branch()

The helper should always be used.
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Oleg Vasilev <oleg.vasilev@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: intel-gfx@lists.freedesktop.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190829114854.1539-2-oleg.vasilev@intel.com

drivers/gpu/drm/drm_dp_helper.c

@@ -460,8 +460,7 @@ void drm_dp_downstream_debug(struct seq_file *m,
 	int len;
 	uint8_t rev[2];
 	int type = port_cap[0] & DP_DS_PORT_TYPE_MASK;
-	bool branch_device = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
-			     DP_DWN_STRM_PORT_PRESENT;
+	bool branch_device = drm_dp_is_branch(dpcd);
 
 	seq_printf(m, "\tDP branch device present: %s\n",
 		   branch_device ? "yes" : "no");

drivers/gpu/drm/i915/display/intel_dp.c

@@ -3149,7 +3149,7 @@ static bool downstream_hpd_needs_d0(struct intel_dp *intel_dp)
 	 * FIXME should really check all downstream ports...
 	 */
 	return intel_dp->dpcd[DP_DPCD_REV] == 0x11 &&
-		intel_dp->dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT &&
+		drm_dp_is_branch(intel_dp->dpcd) &&
 		intel_dp->downstream_ports[0] & DP_DS_PORT_HPD;
 }