From 316bcffe44798d37144e908dea96ad7f8093114c Mon Sep 17 00:00:00 2001 From: Xiaoliang Yang Date: Mon, 19 Apr 2021 18:25:30 +0800 Subject: [PATCH] net: dsa: felix: disable always guard band bit for TAS config ALWAYS_GUARD_BAND_SCH_Q bit in TAS config register is descripted as this: 0: Guard band is implemented for nonschedule queues to schedule queues transition. 1: Guard band is implemented for any queue to schedule queue transition. The driver set guard band be implemented for any queue to schedule queue transition before, which will make each GCL time slot reserve a guard band time that can pass the max SDU frame. Because guard band time could not be set in tc-taprio now, it will use about 12000ns to pass 1500B max SDU. This limits each GCL time interval to be more than 12000ns. This patch change the guard band to be only implemented for nonschedule queues to schedule queues transition, so that there is no need to reserve guard band on each GCL. Users can manually add guard band time for each schedule queues in their configuration if they want. Signed-off-by: Xiaoliang Yang Reviewed-by: Vladimir Oltean Signed-off-by: David S. Miller --- drivers/net/dsa/ocelot/felix_vsc9959.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/dsa/ocelot/felix_vsc9959.c b/drivers/net/dsa/ocelot/felix_vsc9959.c index 789fe08cae50..2473bebe48e6 100644 --- a/drivers/net/dsa/ocelot/felix_vsc9959.c +++ b/drivers/net/dsa/ocelot/felix_vsc9959.c @@ -1227,8 +1227,12 @@ static int vsc9959_qos_port_tas_set(struct ocelot *ocelot, int port, if (taprio->num_entries > VSC9959_TAS_GCL_ENTRY_MAX) return -ERANGE; - ocelot_rmw(ocelot, QSYS_TAS_PARAM_CFG_CTRL_PORT_NUM(port) | - QSYS_TAS_PARAM_CFG_CTRL_ALWAYS_GUARD_BAND_SCH_Q, + /* Set port num and disable ALWAYS_GUARD_BAND_SCH_Q, which means set + * guard band to be implemented for nonschedule queues to schedule + * queues transition. + */ + ocelot_rmw(ocelot, + QSYS_TAS_PARAM_CFG_CTRL_PORT_NUM(port), QSYS_TAS_PARAM_CFG_CTRL_PORT_NUM_M | QSYS_TAS_PARAM_CFG_CTRL_ALWAYS_GUARD_BAND_SCH_Q, QSYS_TAS_PARAM_CFG_CTRL); -- GitLab