static u32 airtime_link_metric_get(struct ieee80211_local *local,
struct sta_info *sta)
{
struct rate_info rinfo;
/* This should be adjusted for each device */
int device_constant = 1 << ARITH_SHIFT;
int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
int s_unit = 1 << ARITH_SHIFT;
int rate, err;
u32 tx_time, estimated_retx;
u64 result;
if (sta->fail_avg >= 100)
return MAX_METRIC;
sta_set_rate_info_tx(sta, &sta->last_tx_rate, &rinfo);
rate = cfg80211_calculate_bitrate(&rinfo);
if (WARN_ON(!rate))
return MAX_METRIC;
err = (sta->fail_avg << ARITH_SHIFT) / 100;
/* bitrate is in units of 100 Kbps, while we need rate in units of
* 1Mbps. This will be corrected on tx_time computation.
*/
tx_time = (device_constant + 10 * test_frame_len / rate);
estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT) ;
return (u32)result;
}
static u32 airtime_link_metric_get(struct ieee80211_local *local,
struct sta_info *sta)
{
struct rate_info rinfo;
/* This should be adjusted for each device */
int device_constant = 1 << ARITH_SHIFT;
int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
int s_unit = 1 << ARITH_SHIFT;
int rate, err;
u32 tx_time, estimated_retx;
u64 result;
unsigned long fail_avg =
ewma_mesh_fail_avg_read(&sta->mesh->fail_avg);
/* Try to get rate based on HW/SW RC algorithm.
* Rate is returned in units of Kbps, correct this
* to comply with airtime calculation units
* Round up in case we get rate < 100Kbps
*/
rate = DIV_ROUND_UP(sta_get_expected_throughput(sta), 100);
if (rate) {
err = 0;
} else {
if (fail_avg > LINK_FAIL_THRESH)
return MAX_METRIC;
sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
rate = cfg80211_calculate_bitrate(&rinfo);
if (WARN_ON(!rate))
return MAX_METRIC;
err = (fail_avg << ARITH_SHIFT) / 100;
}
/* bitrate is in units of 100 Kbps, while we need rate in units of
* 1Mbps. This will be corrected on tx_time computation.
*/
tx_time = (device_constant + 10 * test_frame_len / rate);
estimated_retx = ((1 << (2 * ARITH_SHIFT)) / (s_unit - err));
result = (tx_time * estimated_retx) >> (2 * ARITH_SHIFT);
return (u32)result;
}
