[PATCH net 1/2] r8169: enable rtl8125b pause slot

From: ChunHao Lin
Date: Mon Nov 27 2023 - 12:58:21 EST


When FIFO reach near full state, device will issue pause frame.
If pause slot is enabled(set to 1), in this time, device will issue
pause frame once. But if pause slot is disabled(set to 0), device
will keep sending pause frames until FIFO reach near empty state.

When pause slot is disabled, if there is no one to handle receive
packets (ex. unexpected shutdown), device FIFO will reach near full
state and keep sending pause frames. That will impact entire local
area network.

In this patch default enable pause slot to prevent this kind of
situation.

Fixes: f1bce4ad2f1c ("r8169: add support for RTL8125")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: ChunHao Lin <hau@xxxxxxxxxxx>
---
drivers/net/ethernet/realtek/r8169_main.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 295366a85c63..473b3245754f 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -196,6 +196,7 @@ enum rtl_registers {
/* No threshold before first PCI xfer */
#define RX_FIFO_THRESH (7 << RXCFG_FIFO_SHIFT)
#define RX_EARLY_OFF (1 << 11)
+#define RX_PAUSE_SLOT_ON (1 << 11)
#define RXCFG_DMA_SHIFT 8
/* Unlimited maximum PCI burst. */
#define RX_DMA_BURST (7 << RXCFG_DMA_SHIFT)
@@ -2305,9 +2306,13 @@ static void rtl_init_rxcfg(struct rtl8169_private *tp)
case RTL_GIGA_MAC_VER_40 ... RTL_GIGA_MAC_VER_53:
RTL_W32(tp, RxConfig, RX128_INT_EN | RX_MULTI_EN | RX_DMA_BURST | RX_EARLY_OFF);
break;
- case RTL_GIGA_MAC_VER_61 ... RTL_GIGA_MAC_VER_63:
+ case RTL_GIGA_MAC_VER_61:
RTL_W32(tp, RxConfig, RX_FETCH_DFLT_8125 | RX_DMA_BURST);
break;
+ case RTL_GIGA_MAC_VER_63:
+ RTL_W32(tp, RxConfig, RX_FETCH_DFLT_8125 | RX_DMA_BURST |
+ RX_PAUSE_SLOT_ON);
+ break;
default:
RTL_W32(tp, RxConfig, RX128_INT_EN | RX_DMA_BURST);
break;
--
2.39.2