STPK-1429 Allow for delivery rates up to 1000/s

Lower the forced gap between poll releases to 1/1000s, and
conversely limit the sampling rate we get from upper layers.

Not sure that all involved layers (drivers, HAL module, Android
middleware, applications) react correctly to such sampling rates,
so that could be an area of focus for testing.

Issue: STPK-1429

Change-Id: I431598d3e60123e8d2ad173a56a64eff1d8a0c0c
Signed-off-by: Patrick Porlan <patrick.porlan@intel.com>

diff --git a/control.c b/control.c
index 45b4e2e..56f3d0a 100644 (file)
--- a/control.c
+++ b/control.c
@@ -30,7 +30,7 @@ static int64_t last_poll_exit_ts;
 static int active_poll_sensors; /* Number of enabled poll-mode sensors */
 
 /* Cap the time between poll operations to this, to counter runaway polls */
-#define POLL_MIN_INTERVAL 10000 /* uS */
+#define POLL_MIN_INTERVAL 1000 /* uS */
 
 #define INVALID_DEV_NUM ((uint32_t) -1)
 
@@ -659,8 +659,9 @@ int sensor_set_delay(int s, int64_t ns)
        int dev_num             =       sensor_info[s].dev_num;
        int i                   =       sensor_info[s].catalog_index;
        const char *prefix      =       sensor_catalog[i].tag;
-       int new_sampling_rate;
-       int cur_sampling_rate;
+       int new_sampling_rate;  /* Granted sampling rate after arbitration   */
+       int cur_sampling_rate;  /* Currently used sampling rate              */
+       int req_sampling_rate;  /* Requested ; may be different from granted */
        int per_sensor_sampling_rate;
        int per_device_sampling_rate;
        char freqs_buf[100];
@@ -672,7 +673,7 @@ int sensor_set_delay(int s, int64_t ns)
                return -EINVAL;
        }
 
-       new_sampling_rate = (int) (1000000000L/ns);
+       new_sampling_rate = req_sampling_rate = (int) (1000000000L/ns);
 
        if (!new_sampling_rate) {
                ALOGI("Sub-HZ sampling rate requested on on sensor %d\n", s);
@@ -743,8 +744,8 @@ int sensor_set_delay(int s, int64_t ns)
                         */
                        if (n > new_sampling_rate) {
                                ALOGI(
-                               "Increasing sampling rate on sensor %d to %d\n",
-                               s, n);
+                       "Increasing sampling rate on sensor %d from %d to %d\n",
+                               s, req_sampling_rate, n);
 
                                new_sampling_rate = n;
                                break;
@@ -760,11 +761,20 @@ int sensor_set_delay(int s, int64_t ns)
                }
        }
 
+       /* Cap sampling rates at 1000/s for the time being */
+       if (new_sampling_rate > 1000000/POLL_MIN_INTERVAL) {
+
+               new_sampling_rate = 1000000/POLL_MIN_INTERVAL;
+
+               ALOGI(  "Can't support %d sampling rate, lowering to %d\n",
+                       req_sampling_rate, new_sampling_rate);
+       }
+
        /* If the desired rate is already active we're all set */
        if (new_sampling_rate == cur_sampling_rate)
                return 0;
 
-       ALOGI("Sensor %d sampling rate set to %d\n", s, new_sampling_rate);
+       ALOGI("Sensor %d sampling rate switched to %d\n", s, new_sampling_rate);
 
        if (trig_sensors_per_dev[dev_num])
                enable_buffer(dev_num, 0);