Re: A weird problem of Realtek r8168 after resume from S3

[Heiner Kallweit <hkallweit1@gmail.com>]

On 17.12.2018 14:25, Chris Chiu wrote:
> On Fri, Dec 14, 2018 at 3:37 PM Heiner Kallweit <hkallweit1@gmail.com> wrote:
>>
>> On 14.12.2018 04:33, Chris Chiu wrote:
>>> On Thu, Dec 13, 2018 at 10:20 AM Chris Chiu <chiu@endlessm.com> wrote:
>>>>
>>>> Hi,
>>>>     We got an acer laptop which has a problem with ethernet networking after
>>>> resuming from S3. The ethernet is popular realtek r8168. The lspci shows as
>>>> follows.
>>>> 02:00.1 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd.
>>>> RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev 12)
>>>>
>> Helpful would be a "dmesg | grep r8169", especially chip name + XID.
>>
> [   22.362774] r8169 0000:02:00.1 (unnamed net_device)
> (uninitialized): mac_version = 0x2b
> [   22.365580] libphy: r8169: probed
> [   22.365958] r8169 0000:02:00.1 eth0: RTL8411, 00:e0:b8:1f:cb:83,
> XID 5c800800, IRQ 38
> [   22.365961] r8169 0000:02:00.1 eth0: jumbo features [frames: 9200
> bytes, tx checksumming: ko]
> 
>>>>     The problem is the ethernet is not accessible after resume. Pinging via
>>>> ethernet always shows the response `Destination Host Unreachable`. However,
>>>> the interesting part is, when I run tcpdump to monitor the problematic ethernet
>>>> interface, the networking is back to alive. But it's dead again after
>>>> I stop tcpdump.
>>>> One more thing, if I ping the problematic machine from others, it achieves the
>>>> same effect as above tcpdump. Maybe it's about the register setting for RX path?
>>>>
>> You could compare the register dumps (ethtool -d) before and after S3 sleep
>> to find out whether there's a difference.
>>
> 
> Actually, I just found I lead the wrong direction. The S3 suspend does
> help to reproduce,
> but it's not necessary. All I need to do is ping around 5 mins and the
> network connection
> fails.  And I also find one thing interesting, disabling the  MSI-X
> interrupt like commit
> [d49c88d7677ba737e9d2759a87db0402d5ab2607] can fix this problem.
> Although I don't
> understand the root cause. Anything I can do to help?
> 
One  more thing: I checked the vendor driver and it uses a different sequence
to initialize the ePHY. Could you please check whether the following patch
makes a difference? I don't have much hope but it's worth a try.

diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
index 8462553e3..7cfb22e05 100644
--- a/drivers/net/ethernet/realtek/r8169.c
+++ b/drivers/net/ethernet/realtek/r8169.c
@@ -5097,11 +5097,16 @@ static void rtl_hw_start_8168g_2(struct rtl8169_private *tp)
 static void rtl_hw_start_8411_2(struct rtl8169_private *tp)
 {
 	static const struct ephy_info e_info_8411_2[] = {
-		{ 0x00, 0x0000,	0x0008 },
-		{ 0x0c, 0x3df0,	0x0200 },
-		{ 0x0f, 0xffff,	0x5200 },
-		{ 0x19, 0x0020,	0x0000 },
-		{ 0x1e, 0x0000,	0x2000 }
+		{ 0x00, 0x0008,	0x0000 },
+		{ 0x0c, 0x37d0,	0x0820 },
+		{ 0x1e, 0x0000,	0x0001 },
+		{ 0x19, 0x8021,	0x0000 },
+		{ 0x1e, 0x0000,	0x2000 },
+		{ 0x0d, 0x0100,	0x0200 },
+		{ 0x00, 0x0000,	0x0080 },
+		{ 0x06, 0x0000,	0x0010 },
+		{ 0x04, 0x0000,	0x0010 },
+		{ 0x1d, 0x0000,	0x4000 },
 	};
 
 	rtl_hw_start_8168g(tp);
-- 
2.20.0


>>>>     I tried the latest 4.20 rc version but the problem still there. I
>>>> also tried some
>>>> hw_reset or init thing in the resume path but no effect. Any
>>>> suggestion for this?
>>>> Thanks
>>>>
>> Did previous kernel versions work? If it's a regression, a bisect would be
>> appreciated, because with the chip versions I've got I can't reproduce the issue.
>>
>>>> Chris
>>>
>>> Gentle ping. Any additional information required?
>>>
>>> Chris
>>>
>> Heiner
>