diff options
Diffstat (limited to 'drivers/net/can/usb/peak_usb/pcan_usb_core.c')
-rw-r--r-- | drivers/net/can/usb/peak_usb/pcan_usb_core.c | 57 |
1 files changed, 51 insertions, 6 deletions
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb_core.c b/drivers/net/can/usb/peak_usb/pcan_usb_core.c index 8c47cc8dc896..620db93ab9a3 100644 --- a/drivers/net/can/usb/peak_usb/pcan_usb_core.c +++ b/drivers/net/can/usb/peak_usb/pcan_usb_core.c @@ -150,14 +150,55 @@ void peak_usb_get_ts_tv(struct peak_time_ref *time_ref, u32 ts, /* protect from getting timeval before setting now */ if (time_ref->tv_host.tv_sec > 0) { u64 delta_us; + s64 delta_ts = 0; + + /* General case: dev_ts_1 < dev_ts_2 < ts, with: + * + * - dev_ts_1 = previous sync timestamp + * - dev_ts_2 = last sync timestamp + * - ts = event timestamp + * - ts_period = known sync period (theoretical) + * ~ dev_ts2 - dev_ts1 + * *but*: + * + * - time counters wrap (see adapter->ts_used_bits) + * - sometimes, dev_ts_1 < ts < dev_ts2 + * + * "normal" case (sync time counters increase): + * must take into account case when ts wraps (tsw) + * + * < ts_period > < > + * | | | + * ---+--------+----+-------0-+--+--> + * ts_dev_1 | ts_dev_2 | + * ts tsw + */ + if (time_ref->ts_dev_1 < time_ref->ts_dev_2) { + /* case when event time (tsw) wraps */ + if (ts < time_ref->ts_dev_1) + delta_ts = BIT_ULL(time_ref->adapter->ts_used_bits); + + /* Otherwise, sync time counter (ts_dev_2) has wrapped: + * handle case when event time (tsn) hasn't. + * + * < ts_period > < > + * | | | + * ---+--------+--0-+---------+--+--> + * ts_dev_1 | ts_dev_2 | + * tsn ts + */ + } else if (time_ref->ts_dev_1 < ts) { + delta_ts = -BIT_ULL(time_ref->adapter->ts_used_bits); + } - delta_us = ts - time_ref->ts_dev_2; - if (ts < time_ref->ts_dev_2) - delta_us &= (1 << time_ref->adapter->ts_used_bits) - 1; + /* add delay between last sync and event timestamps */ + delta_ts += (signed int)(ts - time_ref->ts_dev_2); - delta_us += time_ref->ts_total; + /* add time from beginning to last sync */ + delta_ts += time_ref->ts_total; - delta_us *= time_ref->adapter->us_per_ts_scale; + /* convert ticks number into microseconds */ + delta_us = delta_ts * time_ref->adapter->us_per_ts_scale; delta_us >>= time_ref->adapter->us_per_ts_shift; *tv = time_ref->tv_host_0; @@ -841,7 +882,7 @@ static int peak_usb_create_dev(const struct peak_usb_adapter *peak_usb_adapter, if (dev->adapter->dev_set_bus) { err = dev->adapter->dev_set_bus(dev, 0); if (err) - goto lbl_unregister_candev; + goto adap_dev_free; } /* get device number early */ @@ -853,6 +894,10 @@ static int peak_usb_create_dev(const struct peak_usb_adapter *peak_usb_adapter, return 0; +adap_dev_free: + if (dev->adapter->dev_free) + dev->adapter->dev_free(dev); + lbl_unregister_candev: unregister_candev(netdev); |