4.18-stable review patch. If anyone has any objections, please let me know.
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From: "Maciej S. Szmigiero" mail@maciej.szmigiero.name
[ Upstream commit f74dd480cf4e31e12971c58a1d832044db945670 ]
Commit 3559d81e76bf ("r8169: simplify rtl_hw_start_8169") changed order of two register writes: 1) Caused RxConfig to be written before TX / RX is enabled, 2) Caused TxConfig to be written before TX / RX is enabled.
At least on XIDs 10000000 ("RTL8169sb/8110sb") and 18000000 ("RTL8169sc/8110sc") such writes are ignored by the chip, leaving values in these registers intact.
Change 1) was reverted by commit 05212ba8132b42 ("r8169: set RxConfig after tx/rx is enabled for RTL8169sb/8110sb devices"), however change 2) wasn't.
In practice, this caused TxConfig's "InterFrameGap time" and "Max DMA Burst Size per Tx DMA Burst" bits to be zero dramatically reducing TX performance (in my tests it dropped from around 500Mbps to around 50Mbps).
This patch fixes the issue by moving TxConfig register write a bit later in the code so it happens after TX / RX is already enabled.
Fixes: 05212ba8132b42 ("r8169: set RxConfig after tx/rx is enabled for RTL8169sb/8110sb devices") Signed-off-by: Maciej S. Szmigiero mail@maciej.szmigiero.name Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ethernet/realtek/r8169.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -5150,13 +5150,13 @@ static void rtl_hw_start(struct rtl8169
rtl_set_rx_max_size(tp); rtl_set_rx_tx_desc_registers(tp); - rtl_set_tx_config_registers(tp); RTL_W8(tp, Cfg9346, Cfg9346_Lock);
/* Initially a 10 us delay. Turned it into a PCI commit. - FR */ RTL_R8(tp, IntrMask); RTL_W8(tp, ChipCmd, CmdTxEnb | CmdRxEnb); rtl_init_rxcfg(tp); + rtl_set_tx_config_registers(tp);
rtl_set_rx_mode(tp->dev); /* no early-rx interrupts */