linux-kernel - Re: [Intel-wired-lan] [PATCH v4] e1000e: Increase polling timeout on MDIC ready bit

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Date:   Mon, 5 Oct 2020 14:23:55 +0800
From:   Kai-Heng Feng <kai.heng.feng@...onical.com>
To:     Vitaly Lifshits <vitaly.lifshits@...el.com>
Cc:     "Neftin, Sasha" <sasha.neftin@...el.com>,
        Jeff Kirsher <jeffrey.t.kirsher@...el.com>,
        Andrew Lunn <andrew@...n.ch>,
        "open list:NETWORKING DRIVERS" <netdev@...r.kernel.org>,
        open list <linux-kernel@...r.kernel.org>,
        "moderated list:INTEL ETHERNET DRIVERS" 
        <intel-wired-lan@...ts.osuosl.org>,
        Jakub Kicinski <kuba@...nel.org>,
        "David S. Miller" <davem@...emloft.net>,
        "Nguyen, Anthony L" <anthony.l.nguyen@...el.com>
Subject: Re: [Intel-wired-lan] [PATCH v4] e1000e: Increase polling timeout on
 MDIC ready bit

Hi Vitaly,

> On Sep 30, 2020, at 14:54, Vitaly Lifshits <vitaly.lifshits@...el.com> wrote:
> 
> On 9/29/2020 18:08, Kai-Heng Feng wrote:
> 
> Hello Kai-Heng,
>>> On Sep 29, 2020, at 21:46, Neftin, Sasha <sasha.neftin@...el.com> wrote:
>>> 
>>> Hello Kai-Heng,
>>> On 9/29/2020 16:31, Kai-Heng Feng wrote:
>>>> Hi Sasha,
>>>>> On Sep 29, 2020, at 21:08, Neftin, Sasha <sasha.neftin@...el.com> wrote:
>>>>> 
>>>>> On 9/28/2020 11:36, Kai-Heng Feng wrote:
>>>>>> We are seeing the following error after S3 resume:
>>>>>> [  704.746874] e1000e 0000:00:1f.6 eno1: Setting page 0x6020
>>>>>> [  704.844232] e1000e 0000:00:1f.6 eno1: MDI Write did not complete
>>>>>> [  704.902817] e1000e 0000:00:1f.6 eno1: Setting page 0x6020
>>>>>> [  704.903075] e1000e 0000:00:1f.6 eno1: reading PHY page 769 (or 0x6020 shifted) reg 0x17
>>>>>> [  704.903281] e1000e 0000:00:1f.6 eno1: Setting page 0x6020
>>>>>> [  704.903486] e1000e 0000:00:1f.6 eno1: writing PHY page 769 (or 0x6020 shifted) reg 0x17
>>>>>> [  704.943155] e1000e 0000:00:1f.6 eno1: MDI Error
>>>>>> ...
>>>>>> [  705.108161] e1000e 0000:00:1f.6 eno1: Hardware Error
>>>>>> As Andrew Lunn pointed out, MDIO has nothing to do with phy, and indeed
>>>>>> increase polling iteration can resolve the issue.
>>>>>> This patch only papers over the symptom, as we don't really know the
>>>>>> root cause of the issue. The most possible culprit is Intel ME, which
>>>>>> may do its own things that conflict with software.
>>>>>> Signed-off-by: Kai-Heng Feng <kai.heng.feng@...onical.com>
>>>>>> ---
>>>>>> v4:
>>>>>>  - States that this patch just papers over the symptom.
>>>>>> v3:
>>>>>>  - Moving delay to end of loop doesn't save anytime, move it back.
>>>>>>  - Point out this is quitely likely caused by Intel ME.
>>>>>> v2:
>>>>>>  - Increase polling iteration instead of powering down the phy.
>>>>>>  drivers/net/ethernet/intel/e1000e/phy.c | 2 +-
>>>>>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>> diff --git a/drivers/net/ethernet/intel/e1000e/phy.c b/drivers/net/ethernet/intel/e1000e/phy.c
>>>>>> index e11c877595fb..e6d4acd90937 100644
>>>>>> --- a/drivers/net/ethernet/intel/e1000e/phy.c
>>>>>> +++ b/drivers/net/ethernet/intel/e1000e/phy.c
>>>>>> @@ -203,7 +203,7 @@ s32 e1000e_write_phy_reg_mdic(struct e1000_hw *hw, u32 offset, u16 data)
>>>>>>  	 * Increasing the time out as testing showed failures with
>>>>>>  	 * the lower time out
>>>>>>  	 */
>>>>>> -	for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 3); i++) {
>>>>>> +	for (i = 0; i < (E1000_GEN_POLL_TIMEOUT * 10); i++) {
>>>>> As we discussed (many threads) - AMT/ME systems not supported on Linux as properly. I do not think increasing polling iteration will solve the problem. Rather mask it.
>>>> I am aware of the status quo of no proper support on Intel ME.
>>>>> I prefer you check option to disable ME vi BIOS on your system.
>>>> We can't ask user to change the BIOS to accommodate Linux. So before a proper solution comes out, masking the problem is good enough for me.
>>>> Until then, I'll carry it as a downstream distro patch.
>>> What will you do with system that even after increasing polling time will run into HW error?
>> Hope we finally have proper ME support under Linux?
>> Kai-Heng
>>>> Kai-Heng
>>>>>>  		udelay(50);
>>>>>>  		mdic = er32(MDIC);
>>>>>>  		if (mdic & E1000_MDIC_READY)
>>>>> Thanks,
>>>>> Sasha
>>> Thanks,
>>> Sasha
> 
> On which device ID/platform do you see the issue?

HP Z4 G4 Workstation,
00:1f.6 Ethernet controller [0200]: Intel Corporation Ethernet Connection (2) I219-LM [8086:15b7]

> What is the Firmware version on your platform?

BIOS version: P61 v02.59


> What is the ME firmware version that you have?

ME version: 11.11.50.1422
ME mode: AMT disable

Kai-Heng

> 
> I am asking these questions, since I know there is supposed to be a fix in the firmware to many issues that are related to ME and device interoperability.
> 
> Thanks,
> 
> Vitaly