test: add test for fifo pop

Test the case where the entry being removed has fewer than 2 entries
in the fifo. This would trigger us to look at other sensors to see if
timestamp spreading is still needed. The test verifies that the
correct sample is at the head of the sensor data and that the
timestamps were spread.

BRANCH=none
BUG=b:224614211
TEST=make run-motion_sense_fifo -j

Signed-off-by: Yuval Peress <peress@google.com>
Change-Id: I5771247722d0e2cc4b1765d9da2b6d66e649303d
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3575698
Reviewed-by: Keith Short <keithshort@chromium.org>
Commit-Queue: Keith Short <keithshort@chromium.org>

1 files changed, 53 insertions, 0 deletions

diff --git a/test/motion_sense_fifo.c b/test/motion_sense_fifo.c
index 1d6602650c..afa9a4f5cf 100644
--- a/test/motion_sense_fifo.c
+++ b/test/motion_sense_fifo.c
@@ -293,6 +293,58 @@ static int test_spread_data_in_window(void)
 	return EC_SUCCESS;
 }
 
+static int test_spread_data_on_overflow(void)
+{
+	const uint32_t now = __hw_clock_source_read();
+	const int fill_count = (CONFIG_ACCEL_FIFO_SIZE / 2) - 1;
+	int i, read_count;
+
+	/* Set up the sensors */
+	motion_sensors[0].collection_rate = 20; /* us */
+	motion_sensors[0].oversampling_ratio = 1;
+	motion_sensors[1].oversampling_ratio = 1;
+
+	/* Add 1 sample for sensor [1]. This will be evicted. */
+	data->sensor_num = 1;
+	motion_sense_fifo_stage_data(data, motion_sensors + 1, 3, 0);
+
+	/*
+	 * Fill the rest of the fifo, every 2 entries will have the same
+	 * timestamp simulating have 2 entries on the hardware FIFO per read.
+	 */
+	data->sensor_num = 0;
+	for (i = 0; i < fill_count; i++) {
+		int ts = now - ((fill_count - i) / 2) * 10;
+
+		motion_sense_fifo_stage_data(data, motion_sensors, 3, ts);
+	}
+
+	/* Insert an async event which also causes a commit */
+	motion_sense_fifo_insert_async_event(motion_sensors, ASYNC_EVENT_FLUSH);
+
+	read_count =
+		motion_sense_fifo_read(sizeof(data), 4, data, &data_bytes_read);
+
+	/* Verify that we read 4 entries */
+	TEST_EQ(read_count, 4, "%d");
+
+	/* Verify that entries 0 and 2 are timestamps (1 and 3 are data) */
+	TEST_BITS_SET(data[0].flags, MOTIONSENSE_SENSOR_FLAG_TIMESTAMP);
+	TEST_BITS_SET(data[2].flags, MOTIONSENSE_SENSOR_FLAG_TIMESTAMP);
+
+	/*
+	 * Verify that the first read entry is the first one added in the for
+	 * loop above.
+	 */
+	TEST_EQ(data[0].sensor_num, 0, "%u");
+	TEST_EQ(data[0].timestamp, now - ((fill_count - 1) / 2) * 10, "%u");
+
+	/* Verify that the timestamp was spread */
+	TEST_NE(data[0].timestamp, data[2].timestamp, "%u");
+
+	return EC_SUCCESS;
+}
+
 static int test_spread_data_by_collection_rate(void)
 {
 	const uint32_t now = __hw_clock_source_read();
@@ -411,6 +463,7 @@ void run_test(int argc, char **argv)
 	RUN_TEST(test_add_data_no_spreading_when_different_sensors);
 	RUN_TEST(test_add_data_no_spreading_different_timestamps);
 	RUN_TEST(test_spread_data_in_window);
+	RUN_TEST(test_spread_data_on_overflow);
 	RUN_TEST(test_spread_data_by_collection_rate);
 	RUN_TEST(test_spread_double_commit_same_timestamp);
 	RUN_TEST(test_commit_non_data_or_timestamp_entries);