This is a note to let you know that I've just added the patch titled
r8169: fix performance regression related to PCIe max read request size
to the 5.4-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:
r8169-fix-performance-regression-related-to-pcie-max.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a0594ba9f65acd50668b0251a3ef9abbe03cf932
Author: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Date: Wed Feb 5 21:22:46 2020 +0100
r8169: fix performance regression related to PCIe max read request size
[ Upstream commit 21b5f672fb2eb1366dedc4ac9d32431146b378d3 ]
It turned out that on low performance systems the original change can
cause lower tx performance. On a N3450-based mini-PC tx performance
in iperf3 was reduced from 950Mbps to ~900Mbps. Therefore effectively
revert the original change, just use pcie_set_readrq() now instead of
changing the PCIe capability register directly.
Fixes: 2df49d365498 ("r8169: remove fiddling with the PCIe max read request size")
Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 5ca28985c86b..19ebde91555d 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -4099,15 +4099,18 @@ static void rtl_hw_jumbo_enable(struct rtl8169_private *tp)
switch (tp->mac_version) {
case RTL_GIGA_MAC_VER_12:
case RTL_GIGA_MAC_VER_17:
+ pcie_set_readrq(tp->pci_dev, 512);
r8168b_1_hw_jumbo_enable(tp);
break;
case RTL_GIGA_MAC_VER_18 ... RTL_GIGA_MAC_VER_26:
+ pcie_set_readrq(tp->pci_dev, 512);
r8168c_hw_jumbo_enable(tp);
break;
case RTL_GIGA_MAC_VER_27 ... RTL_GIGA_MAC_VER_28:
r8168dp_hw_jumbo_enable(tp);
break;
case RTL_GIGA_MAC_VER_31 ... RTL_GIGA_MAC_VER_33:
+ pcie_set_readrq(tp->pci_dev, 512);
r8168e_hw_jumbo_enable(tp);
break;
default:
@@ -4137,6 +4140,9 @@ static void rtl_hw_jumbo_disable(struct rtl8169_private *tp)
break;
}
rtl_lock_config_regs(tp);
+
+ if (pci_is_pcie(tp->pci_dev) && tp->supports_gmii)
+ pcie_set_readrq(tp->pci_dev, 4096);
}
static void rtl_jumbo_config(struct rtl8169_private *tp, int mtu)
