On Saturday 30 March 2019 at 17:13:24 +0100, Heiner Kallweit wrote: > It was reported that re-introducing ASPM, in combination with RX > interrupt coalescing, results in significantly increased packet > latency, see [0]. Disabling ASPM or RX interrupt coalescing fixes > the issue. Therefore change the driver's default to disable RX > interrupt coalescing. Users still have the option to enable RX > coalescing via ethtool. > > [0] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=925496 > > Fixes: a99790bf5c7f ("r8169: Reinstate ASPM Support") > Reported-by: Mike Crowe <m...@mcrowe.com> > Signed-off-by: Heiner Kallweit <hkallwe...@gmail.com> > --- > drivers/net/ethernet/realtek/r8169.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/realtek/r8169.c > b/drivers/net/ethernet/realtek/r8169.c > index c9ee1c8eb..8a8a4f70d 100644 > --- a/drivers/net/ethernet/realtek/r8169.c > +++ b/drivers/net/ethernet/realtek/r8169.c > @@ -5460,7 +5460,7 @@ static void rtl_hw_start_8168(struct rtl8169_private > *tp) > tp->cp_cmd |= PktCntrDisable | INTT_1; > RTL_W16(tp, CPlusCmd, tp->cp_cmd); > > - RTL_W16(tp, IntrMitigate, 0x5151); > + RTL_W16(tp, IntrMitigate, 0x5100); > > /* Work around for RxFIFO overflow. */ > if (tp->mac_version == RTL_GIGA_MAC_VER_11) { > -- > 2.21.0
Tested-by: Mike Crowe <m...@mcrowe.com> I configured my ASUS BIOS to reenable "EPA Power Saving Mode" and tried running the current state of linux-5.0.y with the above patch applied on top. As expected, packet latency was good immediately after booting. Running "ethtool -c" showed rx-usecs=0, rx-frames=1. Also as expected, manually increasing these to rx-usecs=200, rx-frames=4 caused the latency problem to return. Thanks for finding a way to address this problem without causing both users of ageing motherboards and modern notebooks to scream. Mike.
