[PATCH 4.19 173/247] r8169: fix jumbo packet handling on RTL8168e

From: Greg Kroah-Hartman
Date: Mon Mar 01 2021 - 16:03:51 EST


From: Heiner Kallweit <hkallweit1@xxxxxxxxx>

[ Upstream commit 6cf739131a15e4177e58a1b4f2bede9d5da78552 ]

Josef reported [0] that using jumbo packets fails on RTL8168e.
Aligning the values for register MaxTxPacketSize with the
vendor driver fixes the problem.

[0] https://bugzilla.kernel.org/show_bug.cgi?id=211827

Fixes: d58d46b5d851 ("r8169: jumbo fixes.")
Reported-by: Josef Oškera <joskera@xxxxxxxxxx>
Tested-by: Josef Oškera <joskera@xxxxxxxxxx>
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Link: https://lore.kernel.org/r/b15ddef7-0d50-4320-18f4-6a3f86fbfd3e@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/realtek/r8169.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 6b901bf1cd54d..6fd1a639ec533 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -4365,7 +4365,7 @@ static void r8168dp_hw_jumbo_disable(struct rtl8169_private *tp)

static void r8168e_hw_jumbo_enable(struct rtl8169_private *tp)
{
- RTL_W8(tp, MaxTxPacketSize, 0x3f);
+ RTL_W8(tp, MaxTxPacketSize, 0x24);
RTL_W8(tp, Config3, RTL_R8(tp, Config3) | Jumbo_En0);
RTL_W8(tp, Config4, RTL_R8(tp, Config4) | 0x01);
rtl_tx_performance_tweak(tp, PCI_EXP_DEVCTL_READRQ_512B);
@@ -4373,7 +4373,7 @@ static void r8168e_hw_jumbo_enable(struct rtl8169_private *tp)

static void r8168e_hw_jumbo_disable(struct rtl8169_private *tp)
{
- RTL_W8(tp, MaxTxPacketSize, 0x0c);
+ RTL_W8(tp, MaxTxPacketSize, 0x3f);
RTL_W8(tp, Config3, RTL_R8(tp, Config3) & ~Jumbo_En0);
RTL_W8(tp, Config4, RTL_R8(tp, Config4) & ~0x01);
rtl_tx_performance_tweak(tp, PCI_EXP_DEVCTL_READRQ_4096B);
--
2.27.0