WiFi exponential back off scan enhancement

Correct the comments on exponential back off scan formula.
Rename "exponent" to "base" to match the formula.
Also make the meaning of AP (Access Point vs. Apps Processor)
explicit for struct wifi_scan_cmd_params.

Bug: 26236392
Change-Id: I5873e1c8667dd964d125e37e2f0eeddec79eda13

diff --git a/include/hardware_legacy/gscan.h b/include/hardware_legacy/gscan.h
index 69e4159..d43fa28 100644 (file)
--- a/include/hardware_legacy/gscan.h
+++ b/include/hardware_legacy/gscan.h
@@ -126,11 +126,11 @@ typedef struct {
     byte report_events;
     int max_period; // if max_period is non zero or different than period, then this bucket is
                     // an exponential backoff bucket and the scan period will grow exponentially
-                    // as per formula: actual_period(N) = period ^ (N/(step_count+1))
+                    // as per formula: actual_period(N) = period * (base ^ (N/step_count))
                     // to a maximum period of max_period
-    int exponent;   // for exponential back off bucket: multiplier: new_period=old_period*exponent
-    int step_count; // for exponential back off bucket, number of scans performed at a given
-                    // period and until the exponent is applied
+    int base;       // for exponential back off bucket: multiplier: new_period=old_period*base
+    int step_count; // for exponential back off bucket, number of scans to perform for a given
+                    // period
 
     int num_channels;
     // channels to scan; these may include DFS channels
@@ -140,9 +140,11 @@ typedef struct {
 
 typedef struct {
     int base_period;                    // base timer period in ms
-    int max_ap_per_scan;                // number of APs to store in each scan ientryn the
-                                        // BSSID/RSSI history buffer (keep the highest RSSI APs)
-    int report_threshold_percent;       // in %, when scan buffer is this much full, wake up AP
+    int max_ap_per_scan;                // number of access points to store in each scan entry in
+                                        // the BSSID/RSSI history buffer (keep the highest RSSI
+                                        // access points)
+    int report_threshold_percent;       // in %, when scan buffer is this much full, wake up apps
+                                        // processor
     int report_threshold_num_scans;     // in number of scans, wake up AP after these many scans
     int num_buckets;
     wifi_scan_bucket_spec buckets[MAX_BUCKETS];