This is a note to let you know that I've just added the patch titled
net: ethernet: mtk_eth_soc: fix RX data corruption issue
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-ethernet-mtk_eth_soc-fix-rx-data-corruption-issu.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit fc96efd390daac530f2e39aadf762decfb8b4e17
Author: Daniel Golle <daniel@xxxxxxxxxxxxxx>
Date: Sat Mar 4 13:43:20 2023 +0000
net: ethernet: mtk_eth_soc: fix RX data corruption issue
[ Upstream commit 193250ace270fecd586dd2d0dfbd9cbd2ade977f ]
Fix data corruption issue with SerDes connected PHYs operating at 1.25
Gbps speed where we could previously observe about 30% packet loss while
the bad packet counter was increasing.
As almost all boards with MediaTek MT7622 or MT7986 use either the MT7531
switch IC operating at 3.125Gbps SerDes rate or single-port PHYs using
rate-adaptation to 2500Base-X mode, this issue only got exposed now when
we started trying to use SFP modules operating with 1.25 Gbps with the
BananaPi R3 board.
The fix is to set bit 12 which disables the RX FIFO clear function when
setting up MAC MCR, MediaTek SDK did the same change stating:
"If without this patch, kernel might receive invalid packets that are
corrupted by GMAC."[1]
[1]: https://git01.mediatek.com/plugins/gitiles/openwrt/feeds/mtk-openwrt-feeds/+/d8a2975939a12686c4a95c40db21efdc3f821f63
Fixes: 42c03844e93d ("net-next: mediatek: add support for MediaTek MT7622 SoC")
Tested-by: Bjørn Mork <bjorn@xxxxxxx>
Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
Reviewed-by: Vladimir Oltean <olteanv@xxxxxxxxx>
Reviewed-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Link: https://lore.kernel.org/r/138da2735f92c8b6f8578ec2e5a794ee515b665f.1677937317.git.daniel@xxxxxxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index e3123723522e3..332329cb1ee00 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -566,7 +566,8 @@ static int mtk_mac_finish(struct phylink_config *config, unsigned int mode,
mcr_cur = mtk_r32(mac->hw, MTK_MAC_MCR(mac->id));
mcr_new = mcr_cur;
mcr_new |= MAC_MCR_IPG_CFG | MAC_MCR_FORCE_MODE |
- MAC_MCR_BACKOFF_EN | MAC_MCR_BACKPR_EN | MAC_MCR_FORCE_LINK;
+ MAC_MCR_BACKOFF_EN | MAC_MCR_BACKPR_EN | MAC_MCR_FORCE_LINK |
+ MAC_MCR_RX_FIFO_CLR_DIS;
/* Only update control register when needed! */
if (mcr_new != mcr_cur)
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 2d9186d32bc09..b481d0d46bb16 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -383,6 +383,7 @@
#define MAC_MCR_FORCE_MODE BIT(15)
#define MAC_MCR_TX_EN BIT(14)
#define MAC_MCR_RX_EN BIT(13)
+#define MAC_MCR_RX_FIFO_CLR_DIS BIT(12)
#define MAC_MCR_BACKOFF_EN BIT(9)
#define MAC_MCR_BACKPR_EN BIT(8)
#define MAC_MCR_FORCE_RX_FC BIT(5)
