net: stmmac: fix taprio configuration when base_time is in the past
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: b60189e0 ("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>