Add docs for setSignalStrengthReportingCriteria

Because setSignalStrengthReportingCriteria only
supports a single measurement quantity, provide
further clarification on the applicability of the
API and how it may be used in various situations.

Bug: 110121199
Test: compilation - docstring-only change
Merged-In: If4236070fbc03368e5a78b0cf502cdc4a529a6ed
Change-Id: If4236070fbc03368e5a78b0cf502cdc4a529a6ed
(cherry picked from commit 529d2fffa02451406f013b354fd7c07164f619b1)

2 files changed, 20 insertions, 6 deletions

diff --git a/current.txt b/current.txt
index e490d61435..316bc4348a 100644
--- a/current.txt
+++ b/current.txt
@@ -383,3 +383,6 @@ e362203b941f18bd4cba29a62adfa02453ed00d6be5b72cdb6c4d7e0bf394a40 android.hardwar
 21757d0e5dd4b7e4bd981a4a20531bca3c32271ad9777b17b74eb5a1ea508384 android.hardware.wifi.supplicant@1.1::ISupplicantStaIface
 cd4330c3196bda1d642a32abfe23a7d64ebfbda721940643af6867af3b3f0aa9 android.hardware.wifi.supplicant@1.1::ISupplicantStaIfaceCallback
 10ff2fae516346b86121368ce5790d5accdfcb73983246b813f3d488b66db45a android.hardware.wifi.supplicant@1.1::ISupplicantStaNetwork
+
+# ABI preserving changes to HALs after Android P
+1d19720d4fd38b1095f0f555a4bd92b3b12c9b1d0f560b0e9a474cd6dcc20db6 android.hardware.radio@1.2::IRadio
diff --git a/radio/1.2/IRadio.hal b/radio/1.2/IRadio.hal
index 6463b0fcc0..87b0add5da 100644
--- a/radio/1.2/IRadio.hal
+++ b/radio/1.2/IRadio.hal
@@ -59,19 +59,30 @@ interface IRadio extends @1.1::IRadio {
     /**
      * Sets the signal strength reporting criteria.
      *
-     * The resulting reporting criteria are the AND of all the supplied criteria.
+     * The resulting reporting rules are the AND of all the supplied criteria. For each RAN
+     * The thresholdsDbm and hysteresisDb apply to only the following measured quantities:
+     * -GERAN    - RSSI
+     * -CDMA2000 - RSSI
+     * -UTRAN    - RSCP
+     * -EUTRAN   - RSRP
      *
-     * Note: Reporting criteria must be individually set for each RAN. If unset, reporting criteria
-     * for that RAN are implementation-defined.
+     * Note: Reporting criteria must be individually set for each RAN. For any unset reporting
+     * criteria, the value is implementation-defined.
      *
-     * Response callback is IRadioResponse.setSignalStrengthReportingCriteriaResponse().
+     * Note: As this mechanism generally only constrains reports based on one measured quantity per
+     * RAN, if multiple measured quantities must be used to trigger a report for a given RAN, the
+     * only valid field may be hysteresisMs: hysteresisDb and thresholdsDbm must be set to zero and
+     * length zero respectively. If either hysteresisDb or thresholdsDbm is set, then reports shall
+     * only be triggered by the respective measured quantity, subject to the applied constraints.
+     *
+     * Response callback is IRadioResponse.setSignalStrengthReportingCriteriaResponse()
      *
      * @param serial Serial number of request.
      * @param hysteresisMs A hysteresis time in milliseconds to prevent flapping. A value of 0
      *     disables hysteresis.
      * @param hysteresisDb An interval in dB defining the required magnitude change between reports.
-     *     hysteresisDb must be smaller than the smallest threshold delta. An
-     *     interval value of 0 disables hysteresis.
+     *     hysteresisDb must be smaller than the smallest threshold delta. An interval value of 0
+     *     disables hysteresis.
      * @param thresholdsDbm A vector of trigger thresholds in dBm. A vector size of 0 disables the
      *     use of thresholds for reporting.
      * @param accessNetwork The type of network for which to apply these thresholds.