Re: [PATCH] r8169: don't use MSI-X on RTL8106e

From: Florian Fainelli
Date: Mon Aug 20 2018 - 16:41:04 EST

On 08/16/2018 12:50 PM, Heiner Kallweit wrote:
> On 16.08.2018 21:39, David Miller wrote:
>> From: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>> Date: Thu, 16 Aug 2018 21:37:31 +0200
>>> On 16.08.2018 21:21, David Miller wrote:
>>>> From: <jian-hong@xxxxxxxxxxxx>
>>>> Date: Wed, 15 Aug 2018 14:21:10 +0800
>>>>> Found the ethernet network on ASUS X441UAR doesn't come back on resume
>>>>> from suspend when using MSI-X. The chip is RTL8106e - version 39.
>>>> Heiner, please take a look at this.
>>>> You recently disabled MSI-X on RTL8168g for similar reasons.
>>>> Now that we've seen two chips like this, maybe there is some other
>>>> problem afoot.
>>> Thanks for the hint. I saw it already and just contacted Realtek
>>> whether they are aware of any MSI-X issues with particular chip
>>> versions. With the chip versions I have access to MSI-X works fine.
>>> There's also the theoretical option that the issues are caused by
>>> broken BIOS's. But so far only chip versions have been reported
>>> which are very similar, at least with regard to version number
>>> (2x VER_40, 1x VER_39). So they may share some buggy component.
>>> Let's see whether Realtek can provide some hint.
>>> If more chip versions are reported having problems with MSI-X,
>>> then we could switch to a whitelist or disable MSI-X in general.
>> It could be that we need to reprogram some register(s) on resume,
>> which normally might not be needed, and that is what is causing the
>> problem with some chips.
> Indeed. That's what I'm checking with Realtek.
> In the register list in the r8169 driver there's one entry which
> seems to indicate that there are MSI-X specific settings.
> However this register isn't used, and the r8168 vendor driver
> uses only MSI. And there are no public datasheets.

Stupid question, but should not we be asking the reporter to try again with:

applied? The original report shows the Generic PHY being used, not the
Realtek PHY driver being used, is this possibly contributing to the problem?