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Subject: Re: Regression caused by commit 7bb05b85bc2d ("r8169: don't use MSI-X
 on RTL8106e")
From:   Kai-Heng Feng <kai.heng.feng@canonical.com>
In-Reply-To: <CAPpJ_ecuPysq2SE7=X7ip-3M=4yOcwuu6m_2292WgYA8j6gqjw@mail.gmail.com>
Date:   Wed, 12 Sep 2018 13:57:31 +0800
Cc:     Thomas Gleixner <tglx@linutronix.de>,
        Linux Netdev List <netdev@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Daniel Drake <drake@endlessm.com>
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 <CAPpJ_ecuPysq2SE7=X7ip-3M=4yOcwuu6m_2292WgYA8j6gqjw@mail.gmail.com>
To:     Jian-Hong Pan <jian-hong@endlessm.com>
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at 12:56, Jian-Hong Pan <jian-hong@endlessm.com> wrote:

> 2018-09-12 11:42 GMT+08:00 Kai-Heng Feng <kai.heng.feng@canonical.com>:
>> Hi Jian-Hong,
>>
>> There's a Dell machine with RTL8106e stops to work after S3 since the  
>> commit
>> introduced.
>> So I am wondering if it's possible to revert the commit and use
>> DMI/subsystem id based quirk table?
>>
>> It's because of commit bc976233a872 ("genirq/msi, x86/vector: Prevent
>> reservation mode for non maskable MSI") cleared the reservation mode,  
>> and I
>> can see this after S3:
>>
>> [   94.872838] do_IRQ: 3.33 No irq handler for vector
>>
>> If the device uses MSI-X instead of MSI, the issue doesn't happen  
>> because of
>> reservation mode.
>
> Interesting!  Opposite symptom!
> Could you help try the patch
> https://marc.info/?l=linux-pci&m=153629858601668&w=4 with and without
> reverting the commit?

Same issue after applying this patch. MSI-X works, MSI doesn't work.

>
> If the patch does not work, another suggestion: You can try falling
> back to only PCI_IRQ_LEGACY.

This device is capable of using MSI-X, I don't think falls back to use  
legacy is a good idea.
Instead, using a quirk table should be more appropriate.

Kai-Heng

>
> Regards,
> Jian-Hong Pan
>
>> Hi Thomas,
>>
>> Is it something should be handled by x86 BIOS? Because I don't see this
>> issue when I use Suspend-to-Idle, which doesn't use BIOS to do suspend.
>>
>> Kai-Heng