IRDA-1184: Alternate between triggers depending on sampling rate

The BMC150 accel driver any-motion trigger is too jerky for certain
games such as the "sniper shooter" one, or "doodle jump". Switch back
to continuous event generation mode if a sampling rate above 25 is
requested, which should keep both the launcher (15 events per second)
and games (60 events per second) happy.

Issue: IRDA-1184

Change-Id: I16000d57e17506aa7e7c0a4f83ced7739e01dd01
Signed-off-by: Patrick Porlan <patrick.porlan@intel.com>

diff --git a/control.c b/control.c
index ce02d69..1bdd333 100644 (file)
--- a/control.c
+++ b/control.c
@@ -650,6 +650,26 @@ int sensor_activate(int s, int enabled)
 }
 
 
+static int is_fast_accelerometer (int s)
+{
+       /*
+        * Some games don't react well to accelerometers using any-motion
+        * triggers. Even very low thresholds seem to trip them, and they tend
+        * to request fairly high event rates. Favor continuous triggers if the
+        * sensor is an accelerometer and uses a sampling rate of at least 25.
+        */
+       int catalog_index = sensor_info[s].catalog_index;
+
+       if (sensor_catalog[catalog_index].type != SENSOR_TYPE_ACCELEROMETER)
+               return 0;
+
+       if (sensor_info[s].sampling_rate < 25)
+               return 0;
+
+       return 1;
+}
+
+
 static void enable_motion_trigger (int dev_num)
 {
        /*
@@ -684,7 +704,8 @@ static void enable_motion_trigger (int dev_num)
                    sensor_info[s].enable_count &&
                    sensor_info[s].num_channels &&
                    (!sensor_info[s].motion_trigger_name[0] ||
-                    !sensor_info[s].report_initialized)
+                    !sensor_info[s].report_initialized ||
+                    is_fast_accelerometer(s))
                    )
                        return; /* Nope */
 
@@ -1215,6 +1236,11 @@ int sensor_set_delay(int s, int64_t ns)
 
        sysfs_write_float(sysfs_path, new_sampling_rate);
 
+       /* Switch back to continuous sampling for accelerometer based games */
+       if (is_fast_accelerometer(s) && sensor_info[s].selected_trigger !=
+                                       sensor_info[s].init_trigger_name)
+               setup_trigger(s, sensor_info[s].init_trigger_name);
+
        if (trig_sensors_per_dev[dev_num])
                enable_buffer(dev_num, 1);