From 5cdfe8306631b2224e3f81fc5a1e2721c7a1948b Mon Sep 17 00:00:00 2001 From: Heiner Kallweit Date: Mon, 18 May 2020 22:47:16 +0200 Subject: [PATCH] r8169: work around an irq coalescing related tx timeout In [0] a user reported reproducible tx timeouts on RTL8168f except PktCntrDisable is set and irq coalescing is enabled. Realtek told me that they are not aware of any related hw issue on this chip version, therefore root cause is still unknown. It's not clear whether the issue affects one or more chip versions in general, or whether issue is specific to reporter's system. Due to this level of uncertainty, and due to the fact that I'm aware of this one report only, let's apply the workaround on net-next only. After this change setting irq coalescing via ethtool can reliably avoid the issue on the affected system. [0] https://bugzilla.kernel.org/show_bug.cgi?id=207205 Signed-off-by: Heiner Kallweit Signed-off-by: David S. Miller --- drivers/net/ethernet/realtek/r8169_main.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c index 23f1500928cb7..79817d4ffa476 100644 --- a/drivers/net/ethernet/realtek/r8169_main.c +++ b/drivers/net/ethernet/realtek/r8169_main.c @@ -1871,6 +1871,15 @@ static int rtl_set_coalesce(struct net_device *dev, struct ethtool_coalesce *ec) RTL_W16(tp, IntrMitigate, w); + /* Meaning of PktCntrDisable bit changed from RTL8168e-vl */ + if (rtl_is_8168evl_up(tp)) { + if (!rx_fr && !tx_fr) + /* disable packet counter */ + tp->cp_cmd |= PktCntrDisable; + else + tp->cp_cmd &= ~PktCntrDisable; + } + tp->cp_cmd = (tp->cp_cmd & ~INTT_MASK) | cp01; RTL_W16(tp, CPlusCmd, tp->cp_cmd); rtl_pci_commit(tp); -- 2.30.2