drm/dp_mst: Refactor drm_dp_mst_handle_up_req()

There's a couple of changes here, so to summarize:

* Remove the big ugly mgr->up_req_recv.have_eomt conditional to save on
  indenting
* Store &mgr->up_req_recv.initial_hdr in a variable so we don't keep
  going over 80 character long lines
* De-duplicate code for calling drm_dp_send_up_ack_reply() and getting
  the MSTB via it's GUID
* Remove all of the duplicate calls to memset() and just use a goto
  instead
* Actually do line wrapping
* Remove the unnecessary if (mstb) check before calling
  drm_dp_mst_topology_put_mstb() - we are guaranteed to always have
  mstb != NULL at that point in the function

Cc: Juston Li <juston.li@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Harry Wentland <hwentlan@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190903204645.25487-13-lyude@redhat.com

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 33098084ad701d9ec53945ec6491922befbd77bf..b09f253fadecad791c2590144306ac0bac5b9f31 100644 (file)
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -3272,68 +3272,69 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
 {
        struct drm_dp_sideband_msg_req_body msg;
+       struct drm_dp_sideband_msg_hdr *hdr = &mgr->up_req_recv.initial_hdr;
        struct drm_dp_mst_branch *mstb = NULL;
+       const u8 *guid;
        bool seqno;
 
-       if (!drm_dp_get_one_sb_msg(mgr, true)) {
-               memset(&mgr->up_req_recv, 0,
-                      sizeof(struct drm_dp_sideband_msg_rx));
-               return 0;
-       }
+       if (!drm_dp_get_one_sb_msg(mgr, true))
+               goto out;
 
        if (!mgr->up_req_recv.have_eomt)
                return 0;
 
-       if (!mgr->up_req_recv.initial_hdr.broadcast) {
-               mstb = drm_dp_get_mst_branch_device(mgr,
-                                                   mgr->up_req_recv.initial_hdr.lct,
-                                                   mgr->up_req_recv.initial_hdr.rad);
+       if (!hdr->broadcast) {
+               mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
                if (!mstb) {
-                       DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
-                       memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
-                       return 0;
+                       DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
+                                     hdr->lct);
+                       goto out;
                }
        }
 
-       seqno = mgr->up_req_recv.initial_hdr.seqno;
+       seqno = hdr->seqno;
        drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
 
-       if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
-               drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
+       if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY)
+               guid = msg.u.conn_stat.guid;
+       else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY)
+               guid = msg.u.resource_stat.guid;
+       else
+               goto out;
 
-               if (!mstb)
-                       mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
+       drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno,
+                                false);
 
+       if (!mstb) {
+               mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
                if (!mstb) {
-                       DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
-                       memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
-                       return 0;
+                       DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
+                                     hdr->lct);
+                       goto out;
                }
+       }
 
+       if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
                drm_dp_update_port(mstb, &msg.u.conn_stat);
 
-               DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type);
-               drm_kms_helper_hotplug_event(mgr->dev);
+               DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
+                             msg.u.conn_stat.port_number,
+                             msg.u.conn_stat.legacy_device_plug_status,
+                             msg.u.conn_stat.displayport_device_plug_status,
+                             msg.u.conn_stat.message_capability_status,
+                             msg.u.conn_stat.input_port,
+                             msg.u.conn_stat.peer_device_type);
 
+               drm_kms_helper_hotplug_event(mgr->dev);
        } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
-               drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
-               if (!mstb)
-                       mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
-
-               if (!mstb) {
-                       DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
-                       memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
-                       return 0;
-               }
-
-               DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
+               DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n",
+                             msg.u.resource_stat.port_number,
+                             msg.u.resource_stat.available_pbn);
        }
 
-       if (mstb)
-               drm_dp_mst_topology_put_mstb(mstb);
-
+       drm_dp_mst_topology_put_mstb(mstb);
+out:
        memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
-
        return 0;
 }