From: Yannick Vignon yannick.vignon@nxp.com
[ Upstream commit fe28c53ed71d463e187748b6b10e1130dd72ceeb ]
The Synopsys TSN MAC supports Qbv base times in the past, but only up to a certain limit. As a result, a taprio qdisc configuration with a small base time (for example when treating the base time as a simple phase offset) is not applied by the hardware and silently ignored.
This was observed on an NXP i.MX8MPlus device, but likely affects all TSN-variants of the MAC.
Fix the issue by making sure the base time is in the future, pushing it by an integer amount of cycle times if needed. (a similar check is already done in several other taprio implementations, see for example drivers/net/ethernet/intel/igc/igc_tsn.c#L116 or drivers/net/dsa/sja1105/sja1105_ptp.h#L39).
Fixes: b60189e0392f ("net: stmmac: Integrate EST with TAPRIO scheduler API") Signed-off-by: Yannick Vignon yannick.vignon@nxp.com Link: https://lore.kernel.org/r/20210113131557.24651-2-yannick.vignon@oss.nxp.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c @@ -605,7 +605,8 @@ static int tc_setup_taprio(struct stmmac { u32 size, wid = priv->dma_cap.estwid, dep = priv->dma_cap.estdep; struct plat_stmmacenet_data *plat = priv->plat; - struct timespec64 time; + struct timespec64 time, current_time; + ktime_t current_time_ns; bool fpe = false; int i, ret = 0; u64 ctr; @@ -700,7 +701,22 @@ static int tc_setup_taprio(struct stmmac }
/* Adjust for real system time */ - time = ktime_to_timespec64(qopt->base_time); + priv->ptp_clock_ops.gettime64(&priv->ptp_clock_ops, ¤t_time); + current_time_ns = timespec64_to_ktime(current_time); + if (ktime_after(qopt->base_time, current_time_ns)) { + time = ktime_to_timespec64(qopt->base_time); + } else { + ktime_t base_time; + s64 n; + + n = div64_s64(ktime_sub_ns(current_time_ns, qopt->base_time), + qopt->cycle_time); + base_time = ktime_add_ns(qopt->base_time, + (n + 1) * qopt->cycle_time); + + time = ktime_to_timespec64(base_time); + } + priv->plat->est->btr[0] = (u32)time.tv_nsec; priv->plat->est->btr[1] = (u32)time.tv_sec;