From e669ce46740a9815953bb4452a6bc5a7fdc21a50 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Fri, 31 Mar 2023 14:49:59 +0200 Subject: net: ethernet: mtk_eth_soc: fix remaining throughput regression Based on further tests, it seems that the QDMA shaper is not able to perform shaping close to the MAC link rate without throughput loss. This cannot be compensated by increasing the shaping rate, so it seems to be an internal limit. Fix the remaining throughput regression by detecting that condition and limiting shaping to ports with lower link speed. This patch intentionally ignores link speed gain from TRGMII, because even on such links, shaping to 1000 Mbit/s incurs some throughput degradation. Fixes: f63959c7eec3 ("net: ethernet: mtk_eth_soc: implement multi-queue support for per-port queues") Tested-By: Frank Wunderlich Reported-by: Frank Wunderlich Signed-off-by: Felix Fietkau Signed-off-by: David S. Miller --- drivers/net/ethernet/mediatek/mtk_eth_soc.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/net/ethernet/mediatek') diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c index 282f9435d5ff..e14050e17862 100644 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -753,6 +753,7 @@ static void mtk_mac_link_up(struct phylink_config *config, MAC_MCR_FORCE_RX_FC); /* Configure speed */ + mac->speed = speed; switch (speed) { case SPEED_2500: case SPEED_1000: @@ -3235,6 +3236,9 @@ found: if (dp->index >= MTK_QDMA_NUM_QUEUES) return NOTIFY_DONE; + if (mac->speed > 0 && mac->speed <= s.base.speed) + s.base.speed = 0; + mtk_set_queue_speed(eth, dp->index + 3, s.base.speed); return NOTIFY_DONE; -- cgit v1.2.3