diff options
Diffstat (limited to 'drivers/platform')
| -rw-r--r-- | drivers/platform/chrome/cros_ec_sensorhub_ring.c | 94 |
1 files changed, 33 insertions, 61 deletions
diff --git a/drivers/platform/chrome/cros_ec_sensorhub_ring.c b/drivers/platform/chrome/cros_ec_sensorhub_ring.c index b1c641c72f51..8921f24e83ba 100644 --- a/drivers/platform/chrome/cros_ec_sensorhub_ring.c +++ b/drivers/platform/chrome/cros_ec_sensorhub_ring.c @@ -673,29 +673,22 @@ done_with_this_batch: * cros_ec_sensor_ring_spread_add_legacy: Calculate proper timestamps then * add to ringbuffer (legacy). * - * Note: This assumes we're running old firmware, where every sample's timestamp - * is after the sample. Run if tight_timestamps == false. - * - * If there is a sample with a proper timestamp + * Note: This assumes we're running old firmware, where timestamp + * is inserted after its sample(s)e. There can be several samples between + * timestamps, so several samples can have the same timestamp. * * timestamp | count * ----------------- - * older_unprocess_out --> TS1 | 1 - * TS1 | 2 - * out --> TS1 | 3 - * next_out --> TS2 | - * - * We spread time for the samples [older_unprocess_out .. out] - * between TS1 and TS2: [TS1+1/4, TS1+2/4, TS1+3/4, TS2]. + * 1st sample --> TS1 | 1 + * TS2 | 2 + * TS2 | 3 + * TS3 | 4 + * last_out --> * - * If we reach the end of the samples, we compare with the - * current timestamp: * - * older_unprocess_out --> TS1 | 1 - * TS1 | 2 - * out --> TS1 | 3 + * We spread time for the samples using perod p = (current - TS1)/4. + * between TS1 and TS2: [TS1+p/4, TS1+2p/4, TS1+3p/4, current_timestamp]. * - * We know have [TS1+1/3, TS1+2/3, current timestamp] */ static void cros_ec_sensor_ring_spread_add_legacy(struct cros_ec_sensorhub *sensorhub, @@ -708,58 +701,37 @@ cros_ec_sensor_ring_spread_add_legacy(struct cros_ec_sensorhub *sensorhub, int i; for_each_set_bit(i, &sensor_mask, sensorhub->sensor_num) { - s64 older_timestamp; s64 timestamp; - struct cros_ec_sensors_ring_sample *older_unprocess_out = - sensorhub->ring; - struct cros_ec_sensors_ring_sample *next_out; - int count = 1; - - for (out = sensorhub->ring; out < last_out; out = next_out) { - s64 time_period; + int count = 0; + s64 time_period; - next_out = out + 1; + for (out = sensorhub->ring; out < last_out; out++) { if (out->sensor_id != i) continue; /* Timestamp to start with */ - older_timestamp = out->timestamp; - - /* Find next sample. */ - while (next_out < last_out && next_out->sensor_id != i) - next_out++; + timestamp = out->timestamp; + out++; + count = 1; + break; + } + for (; out < last_out; out++) { + /* Find last sample. */ + if (out->sensor_id != i) + continue; + count++; + } + if (count == 0) + continue; - if (next_out >= last_out) { - timestamp = current_timestamp; - } else { - timestamp = next_out->timestamp; - if (timestamp == older_timestamp) { - count++; - continue; - } - } + /* Spread uniformly between the first and last samples. */ + time_period = div_s64(current_timestamp - timestamp, count); - /* - * The next sample has a new timestamp, spread the - * unprocessed samples. - */ - if (next_out < last_out) - count++; - time_period = div_s64(timestamp - older_timestamp, - count); - - for (; older_unprocess_out <= out; - older_unprocess_out++) { - if (older_unprocess_out->sensor_id != i) - continue; - older_timestamp += time_period; - older_unprocess_out->timestamp = - older_timestamp; - } - count = 1; - /* The next_out sample has a valid timestamp, skip. */ - next_out++; - older_unprocess_out = next_out; + for (out = sensorhub->ring; out < last_out; out++) { + if (out->sensor_id != i) + continue; + timestamp += time_period; + out->timestamp = timestamp; } } |