From 81496b72e9ba1999d4ed7bb7fa407a1edef020a4 Mon Sep 17 00:00:00 2001
From: Heiner Kallweit <hkallweit1@gmail.com>
Date: Thu, 30 Apr 2020 21:59:48 +0200
Subject: [PATCH] r8169: add check for invalid parameter combination in rtl_set_coalesce
Git-commit: 81496b72e9ba1999d4ed7bb7fa407a1edef020a4
Patch-mainline: v5.8-rc1
References: bsc#1175746
Realtek provided information about a HW constraint that time limit must
not be set to 0 if the frame limit is >0. Add a check for this and
reject invalid parameter combinations.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/net/ethernet/realtek/r8169_main.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 4fe8b1d35b69..aa3e63e031da 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -1908,6 +1908,11 @@ static int rtl_set_coalesce(struct net_device *dev, struct ethtool_coalesce *ec)
if (tx_fr == 1)
tx_fr = 0;
+ /* HW requires time limit to be set if frame limit is set */
+ if ((tx_fr && !ec->tx_coalesce_usecs) ||
+ (rx_fr && !ec->rx_coalesce_usecs))
+ return -EINVAL;
+
w |= FIELD_PREP(RTL_COALESCE_TX_FRAMES, DIV_ROUND_UP(tx_fr, 4));
w |= FIELD_PREP(RTL_COALESCE_RX_FRAMES, DIV_ROUND_UP(rx_fr, 4));
--
2.16.4