On Fri, 19 Jul 2019, Heiner Kallweit wrote:

> On 18.07.2019 20:50, Thomas Voegtle wrote:
>>
>> Hello,
>>
>> I'm having network problems with the commits on r8169 since v5.2. There are ping packet loss, sometimes 100%, sometimes 50%. In the end network is unusable.
>>
>> v5.2 is fine, I bisected it down to:
>>
>> a2928d28643e3c064ff41397281d20c445525032 is the first bad commit
>> commit a2928d28643e3c064ff41397281d20c445525032
>> Author: Heiner Kallweit <hkallweit1@gmail.com>
>> Date:   Sun Jun 2 10:53:49 2019 +0200
>>
>>     r8169: use paged versions of phylib MDIO access functions
>>
>>     Use paged versions of phylib MDIO access functions to simplify
>>     the code.
>>
>>     Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
>>     Signed-off-by: David S. Miller <davem@davemloft.net>
>>
>>
>> Reverting that commit on top of v5.2-11564-g22051d9c4a57 fixes the problem
>> for me (had to adjust the renaming to r8169_main.c).
>>
>> I have a:
>> 04:00.0 Ethernet controller [0200]: Realtek Semiconductor Co., Ltd.
>> RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller [10ec:8168] (rev
>> 0c)
>>         Subsystem: Biostar Microtech Int'l Corp Device [1565:2400]
>>         Kernel driver in use: r8169
>>
>> on a BIOSTAR H81MG motherboard.
>>
> Interesting. I have the same chip version (RTL8168g) and can't reproduce
> the issue. Can you provide a full dmesg output and test the patch below
> on top of linux-next? I'd be interested in the WARN_ON stack traces
> (if any) and would like to know whether the experimental change to
> __phy_modify_changed helps.
>
>>
>> greetings,
>>
>>   Thomas
>>
>>
> Heiner
>
>
> diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
> index 8d7dd4c5f..26be73000 100644
> --- a/drivers/net/ethernet/realtek/r8169_main.c
> +++ b/drivers/net/ethernet/realtek/r8169_main.c
> @@ -1934,6 +1934,8 @@ static int rtl_get_eee_supp(struct rtl8169_private *tp)
> 	struct phy_device *phydev = tp->phydev;
> 	int ret;
>
> +	WARN_ON(phy_read(phydev, 0x1f));
> +
> 	switch (tp->mac_version) {
> 	case RTL_GIGA_MAC_VER_34:
> 	case RTL_GIGA_MAC_VER_35:
> @@ -1957,6 +1959,8 @@ static int rtl_get_eee_lpadv(struct rtl8169_private *tp)
> 	struct phy_device *phydev = tp->phydev;
> 	int ret;
>
> +	WARN_ON(phy_read(phydev, 0x1f));
> +
> 	switch (tp->mac_version) {
> 	case RTL_GIGA_MAC_VER_34:
> 	case RTL_GIGA_MAC_VER_35:
> @@ -1980,6 +1984,8 @@ static int rtl_get_eee_adv(struct rtl8169_private *tp)
> 	struct phy_device *phydev = tp->phydev;
> 	int ret;
>
> +	WARN_ON(phy_read(phydev, 0x1f));
> +
> 	switch (tp->mac_version) {
> 	case RTL_GIGA_MAC_VER_34:
> 	case RTL_GIGA_MAC_VER_35:
> @@ -2003,6 +2009,8 @@ static int rtl_set_eee_adv(struct rtl8169_private *tp, int val)
> 	struct phy_device *phydev = tp->phydev;
> 	int ret = 0;
>
> +	WARN_ON(phy_read(phydev, 0x1f));
> +
> 	switch (tp->mac_version) {
> 	case RTL_GIGA_MAC_VER_34:
> 	case RTL_GIGA_MAC_VER_35:
> diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
> index 16667fbac..1aa1142b8 100644
> --- a/drivers/net/phy/phy-core.c
> +++ b/drivers/net/phy/phy-core.c
> @@ -463,12 +463,10 @@ int __phy_modify_changed(struct phy_device *phydev, u32 regnum, u16 mask,
> 		return ret;
>
> 	new = (ret & ~mask) | set;
> -	if (new == ret)
> -		return 0;
>
> -	ret = __phy_write(phydev, regnum, new);
> +	__phy_write(phydev, regnum, new);
>
> -	return ret < 0 ? ret : 1;
> +	return new != ret;
> }
> EXPORT_SYMBOL_GPL(__phy_modify_changed);
>
>

Took your patch on top of next-20190719.
See attached dmesg.
It didn't work. Same thing, lots of ping drops, no usable network.

like that:
44 packets transmitted, 2 received, 95% packet loss, time 44005ms


Maybe important:
I build a kernel with no modules.

I have to power off when I booted a kernel which doesn't work, a (soft) 
reboot into a older kernel (e.g. 4.9.y)  doesn't
fix the problem. Powering off and on does.


greetings,

       Thomas