[PATCH 6.0 0950/1073] net: ethernet: mtk_eth_soc: drop packets to WDMA if the ring is full

Greg Kroah-Hartman
2022-12-28T16:42:41Z

From: Felix Fietkau <nbd@nbd.name>

[ Upstream commit f4b2fa2c25e1ade78f766aa82e733a0b5198d484 ]

Improves handling of DMA ring overflow.
Clarify other WDMA drop related comment.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20221116080734.44013-3-nbd@nbd.name
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 5 ++++-
drivers/net/ethernet/mediatek/mtk_eth_soc.h | 1 +
2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 4c16f2df566f..559c7a42c1c9 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -3344,9 +3344,12 @@ static int mtk_hw_init(struct mtk_eth *eth)
mtk_w32(eth, 0x21021000, MTK_FE_INT_GRP);

if (MTK_HAS_CAPS(eth->soc->caps, MTK_NETSYS_V2)) {
- /* PSE should not drop port8 and port9 packets */
+ /* PSE should not drop port8 and port9 packets from WDMA Tx */
mtk_w32(eth, 0x00000300, PSE_DROP_CFG);

+ /* PSE should drop packets to port 8/9 on WDMA Rx ring full */
+ mtk_w32(eth, 0x00000300, PSE_PPE0_DROP);
+
/* PSE Free Queue Flow Control */
mtk_w32(eth, 0x01fa01f4, PSE_FQFC_CFG2);

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index da261dd49d6f..df8e6e95254e 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -121,6 +121,7 @@
#define PSE_FQFC_CFG1 0x100
#define PSE_FQFC_CFG2 0x104
#define PSE_DROP_CFG 0x108
+#define PSE_PPE0_DROP 0x110

/* PSE Input Queue Reservation Register*/
#define PSE_IQ_REV(x) (0x140 + (((x) - 1) << 2))
--
2.35.1