diff options
Diffstat (limited to 'drivers/net/dsa/sja1105/sja1105_main.c')
| -rw-r--r-- | drivers/net/dsa/sja1105/sja1105_main.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c index 331bb1c6676a..3f17c17ff636 100644 --- a/drivers/net/dsa/sja1105/sja1105_main.c +++ b/drivers/net/dsa/sja1105/sja1105_main.c @@ -2150,6 +2150,7 @@ static int sja1105_setup_tc_cbs(struct dsa_switch *ds, int port, { struct sja1105_private *priv = ds->priv; struct sja1105_cbs_entry *cbs; + s64 port_transmit_rate_kbps; int index; if (!offload->enable) @@ -2167,9 +2168,17 @@ static int sja1105_setup_tc_cbs(struct dsa_switch *ds, int port, */ cbs->credit_hi = offload->hicredit; cbs->credit_lo = abs(offload->locredit); - /* User space is in kbits/sec, hardware in bytes/sec */ - cbs->idle_slope = offload->idleslope * BYTES_PER_KBIT; - cbs->send_slope = abs(offload->sendslope * BYTES_PER_KBIT); + /* User space is in kbits/sec, while the hardware in bytes/sec times + * link speed. Since the given offload->sendslope is good only for the + * current link speed anyway, and user space is likely to reprogram it + * when that changes, don't even bother to track the port's link speed, + * but deduce the port transmit rate from idleslope - sendslope. + */ + port_transmit_rate_kbps = offload->idleslope - offload->sendslope; + cbs->idle_slope = div_s64(offload->idleslope * BYTES_PER_KBIT, + port_transmit_rate_kbps); + cbs->send_slope = div_s64(abs(offload->sendslope * BYTES_PER_KBIT), + port_transmit_rate_kbps); /* Convert the negative values from 64-bit 2's complement * to 32-bit 2's complement (for the case of 0x80000000 whose * negative is still negative). |