drm/dp/mst: Provide defines for ACK vs. NAK reply type

Make the code a bit easier to read by providing symbolic names
for the reply_type (ACK vs. NAK). Also clean up some brace stuff
while at it.

v2: s/DP_REPLY/DP_SIDEBAND_REPLY/ (DK)
    Fix some checkpatch issues

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190122200301.18633-1-ville.syrjala@linux.intel.com

2 files changed, 17 insertions, 13 deletions

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 2552a27362a0..3d8e8cc0228f 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -568,7 +568,7 @@ static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
         msg->reply_type = (raw->msg[0] & 0x80) >> 7;
         msg->req_type = (raw->msg[0] & 0x7f);
 
-        if (msg->reply_type) {
+        if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
                 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
                 msg->u.nak.reason = raw->msg[17];
                 msg->u.nak.nak_data = raw->msg[18];
@@ -1969,9 +1969,9 @@ static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
         if (ret > 0) {
                 int i;
 
-                if (txmsg->reply.reply_type == 1)
+                if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
                         DRM_DEBUG_KMS("link address nak received\n");
-                else {
+                } else {
                         DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
                                 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", i,
@@ -2020,9 +2020,9 @@ static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
 
         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
         if (ret > 0) {
-                if (txmsg->reply.reply_type == 1)
+                if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
                         DRM_DEBUG_KMS("enum path resources nak received\n");
-                else {
+                } else {
                         if (port->port_num != txmsg->reply.u.path_resources.port_number)
                                 DRM_ERROR("got incorrect port in response\n");
                         DRM_DEBUG_KMS("enum path resources %d: %d %d\n", txmsg->reply.u.path_resources.port_number, txmsg->reply.u.path_resources.full_payload_bw_number,
@@ -2132,7 +2132,7 @@ static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
          */
         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
         if (ret > 0) {
-                if (txmsg->reply.reply_type == 1)
+                if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
                         ret = -EINVAL;
                 else
                         ret = 0;
@@ -2165,7 +2165,7 @@ int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
 
         ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
         if (ret > 0) {
-                if (txmsg->reply.reply_type == 1)
+                if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
                         ret = -EINVAL;
                 else
                         ret = 0;
@@ -2423,9 +2423,9 @@ static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
 
         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
         if (ret > 0) {
-                if (txmsg->reply.reply_type == 1) {
+                if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
                         ret = -EINVAL;
-                } else
+                else
                         ret = 0;
         }
         kfree(txmsg);
@@ -2438,7 +2438,7 @@ static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req
 {
         struct drm_dp_sideband_msg_reply_body reply;
 
-        reply.reply_type = 0;
+        reply.reply_type = DP_SIDEBAND_REPLY_ACK;
         reply.req_type = req_type;
         drm_dp_encode_sideband_reply(&reply, msg);
         return 0;
@@ -2745,9 +2745,9 @@ static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
                 }
 
                 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
-                if (txmsg->reply.reply_type == 1) {
+
+                if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
                         DRM_DEBUG_KMS("Got NAK reply: req 0x%02x, reason 0x%02x, nak data 0x%02x\n", txmsg->reply.req_type, txmsg->reply.u.nak.reason, txmsg->reply.u.nak.nak_data);
-                }
 
                 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
                 drm_dp_mst_topology_put_mstb(mstb);
@@ -3893,7 +3893,7 @@ static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs
         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
         if (ret > 0) {
 
-                if (txmsg->reply.reply_type == 1) { /* got a NAK back */
+                if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
                         ret = -EREMOTEIO;
                         goto out;
                 }
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index c223c87ef119..a62d3750663a 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -992,6 +992,10 @@
 #define DP_SINK_EVENT_NOTIFY            0x30
 #define DP_QUERY_STREAM_ENC_STATUS      0x38
 
+/* DP 1.2 MST sideband reply types */
+#define DP_SIDEBAND_REPLY_ACK           0x00
+#define DP_SIDEBAND_REPLY_NAK           0x01
+
 /* DP 1.2 MST sideband nak reasons - table 2.84 */
 #define DP_NAK_WRITE_FAILURE            0x01
 #define DP_NAK_INVALID_READ             0x02