[PATCH net v3 1/5] net: mvneta: lift the per-queue TX rate limits

[Josef Schlehofer]

The per-queue rate limits set by mqprio stay in effect after the
shaper is turned off.

mvneta_disable_per_queue_rate_limit() only changes the mode bits in
MVNETA_TXQ_CMD1_REG. The token buckets keep limiting the TX queues
with that mode as well, and their refill rate still holds the old
limit.

Refill the token buckets of all TX queues at full rate when the rate
limit is disabled. Deleting the qdisc reaches this code only with the
next patch.

Tested on a Turris Omnia (Armada 385) with 10 Mbit/s limits on a
100 Mbit/s link. When mqprio was set up again without a shaper, each
TX queue stayed at 10 Mbit/s. With this patch the link reaches
94 Mbit/s.

Fixes: 2551dc9e398c ("net: mvneta: Add TC traffic shaping offload")
Signed-off-by: Josef Schlehofer <pepe.schlehofer@xxxxxxxxx>
Reviewed-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
---
 drivers/net/ethernet/marvell/mvneta.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index ea755cf05b9e..9b9efac2846e 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -5204,9 +5204,16 @@ static int mvneta_enable_per_queue_rate_limit(struct mvneta_port *pp)
 static void mvneta_disable_per_queue_rate_limit(struct mvneta_port *pp)
 {
 	u32 val = mvreg_read(pp, MVNETA_TXQ_CMD1_REG);
+	int queue;
 
 	val |= (MVNETA_TXQ_CMD1_BW_LIM_SEL_V1 | MVNETA_TXQ_CMD1_BW_LIM_EN);
 	mvreg_write(pp, MVNETA_TXQ_CMD1_REG, val);
+
+	/* The token buckets still limit the queues, refill them at full rate */
+	val = (1 << MVNETA_TXQ_BUCKET_REFILL_PERIOD_SHIFT) |
+	      MVNETA_TXQ_BUCKET_REFILL_VALUE_MAX;
+	for (queue = 0; queue < txq_number; queue++)
+		mvreg_write(pp, MVNETA_TXQ_BUCKET_REFILL_REG(queue), val);
 }
 
 static int mvneta_setup_queue_rates(struct mvneta_port *pp, int queue,
-- 
2.54.0 (Apple Git-157)