qcacmn: Redefine conditions to skip CAC

Find out if a VAP is going through restart transition and skip CAC.
All other cases, do not skip CAC based on subset logic.
Also, if the channel is non-DFS, do not do CAC.

CRs-Fixed: 2945741
Change-Id: I5a9de47a879eb8d294dfed126a77970c52b2b546

umac/dfs/core/src/dfs.h

@@ -2157,13 +2157,16 @@ void dfs_stacac_stop(struct wlan_dfs *dfs);
  * @continue_current_cac: If AP can start CAC then this variable indicates
  * whether to continue with the current CAC or restart the CAC. This variable
  * is valid only if this function returns true.
+ * @is_vap_restart: Flag to indicate if vap is restarted/started.
+ * True: VAP restart. False: VAP start
  *
  * Return: true if AP requires CAC or can continue current CAC, else false.
  */
 bool dfs_is_cac_required(struct wlan_dfs *dfs,
 			 struct dfs_channel *cur_chan,
 			 struct dfs_channel *prev_chan,
-			 bool *continue_current_cac);
+			 bool *continue_current_cac,
+			 bool is_vap_restart);
 
 /**
  * dfs_cac_stop() - Clear the AP CAC timer.
@@ -2245,7 +2248,8 @@ static inline
 bool dfs_is_cac_required(struct wlan_dfs *dfs,
 			 struct dfs_channel *cur_chan,
 			 struct dfs_channel *prev_chan,
-			 bool *continue_current_cac)
+			 bool *continue_current_cac,
+			 bool is_vap_restart)
 {
 	return false;
 }

umac/dfs/core/src/misc/dfs_cac.c

@@ -402,10 +402,16 @@ dfs_is_new_chan_subset_of_old_chan(struct wlan_dfs *dfs,
 bool dfs_is_cac_required(struct wlan_dfs *dfs,
 			 struct dfs_channel *cur_chan,
 			 struct dfs_channel *prev_chan,
-			 bool *continue_current_cac)
+			 bool *continue_current_cac,
+			 bool is_vap_restart)
 {
 	struct dfs_channel *cac_started_chan = &dfs->dfs_cac_started_chan;
 
+	if (!WLAN_IS_PRIMARY_OR_SECONDARY_CHAN_DFS(cur_chan)) {
+		dfs_debug(dfs, WLAN_DEBUG_DFS, "Skip CAC on non-DFS channel");
+		return false;
+	}
+
 	if (dfs->dfs_ignore_dfs || dfs->dfs_cac_valid || dfs->dfs_ignore_cac) {
 		dfs_debug(dfs, WLAN_DEBUG_DFS,
 			  "Skip CAC, ignore_dfs = %d cac_valid = %d ignore_cac = %d",
@@ -453,6 +459,19 @@ bool dfs_is_cac_required(struct wlan_dfs *dfs,
 			dfs_cancel_cac_timer(dfs);
 		}
 	} else { /* CAC timer is not running. */
+		/* If channel change happens via VAP DOWN/UP on subset channels,
+		 * (eg: from 52 HT80 to 64 HT80) CAC done information
+		 * (of 52 HT80) based on subset logic
+		 * (as 52 and 64 HT80 are subsets of each other)
+		 * is not expected to be preserved as VAP has come up
+		 * from DOWN state. Hence do not skip CAC on 64 HT80.
+		 * is_vap_restart flag is used as an identifer to indicate if
+		 * vap has come up from a DOWN state or UP state (vap restart).
+		 */
+		if (!is_vap_restart) {
+			dfs_debug(dfs, WLAN_DEBUG_DFS, "CAC is needed");
+			return true;
+		}
 		if (dfs_is_new_chan_subset_of_old_chan(dfs,
 						       cur_chan,
 						       prev_chan)) {

umac/dfs/dispatcher/inc/wlan_dfs_utils_api.h

@@ -857,6 +857,8 @@ bool utils_dfs_is_cac_required(struct wlan_objmgr_pdev *pdev,
  * @continue_current_cac: If AP can start CAC then this variable indicates
  * whether to continue with the current CAC or restart the CAC. This variable
  * is valid only if this function returns true.
+ * @is_vap_restart: Flag to indicate if vap is restarted/started.
+ * True: VAP restart. False: VAP start
  *
  * This API checks if the dfs_curchan is a subset of the dfs_prevchan.
  * dfs_curchan and dfs_prevchan are updated after start response by
@@ -866,7 +868,8 @@ bool utils_dfs_is_cac_required(struct wlan_objmgr_pdev *pdev,
  */
 bool
 utils_dfs_is_cac_required_on_dfs_curchan(struct wlan_objmgr_pdev *pdev,
-					 bool *continue_current_cac);
+					 bool *continue_current_cac,
+					 bool is_vap_restart);
 
 /** utils_dfs_is_precac_done() - Check if precac has been done in chosen channel
  * @pdev: Pointer to DFS pdev object.

umac/dfs/dispatcher/src/wlan_dfs_utils_api.c

@@ -305,12 +305,13 @@ bool utils_dfs_is_cac_required(struct wlan_objmgr_pdev *pdev,
 	return dfs_is_cac_required(dfs,
 				   &cur_channel,
 				   &prev_channel,
-				   continue_current_cac);
+				   continue_current_cac, true);
 }
 
 bool
 utils_dfs_is_cac_required_on_dfs_curchan(struct wlan_objmgr_pdev *pdev,
-					 bool *continue_current_cac)
+					 bool *continue_current_cac,
+					 bool is_vap_restart)
 {
 	struct wlan_dfs *dfs;
 
@@ -321,7 +322,8 @@ utils_dfs_is_cac_required_on_dfs_curchan(struct wlan_objmgr_pdev *pdev,
 	return dfs_is_cac_required(dfs,
 				   dfs->dfs_curchan,
 				   dfs->dfs_prevchan,
-				   continue_current_cac);
+				   continue_current_cac,
+				   is_vap_restart);
 }
 
 QDF_STATUS utils_dfs_stacac_stop(struct wlan_objmgr_pdev *pdev)