Date:   Thu, 27 Sep 2018 17:03:24 +0800
From:   Jian-Hong Pan <jian-hong@...lessm.com>
To:     andy.shevchenko@...il.com
Cc:     Kai-Heng Feng <kai.heng.feng@...onical.com>,
        Heiner Kallweit <hkallweit1@...il.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Linux Netdev List <netdev@...r.kernel.org>,
        Linux Kernel <linux-kernel@...r.kernel.org>,
        Linux Upstreaming Team <linux@...lessm.com>,
        Daniel Drake <drake@...lessm.com>,
        Steve Dodd <steved424@...il.com>
Subject: Re: Regression caused by commit 7bb05b85bc2d ("r8169: don't use MSI-X
 on RTL8106e")

Andy Shevchenko <andy.shevchenko@...il.com> 於 2018年9月22日 週六 上午1:08寫道：
>
> On Thu, Sep 13, 2018 at 8:53 AM Jian-Hong Pan <jian-hong@...lessm.com> wrote:
> >
> > 2018-09-12 16:19 GMT+08:00 Kai-Heng Feng <kai.heng.feng@...onical.com>:
> > > at 14:32, Thomas Gleixner <tglx@...utronix.de> wrote:
> > >
> > >> On Wed, 12 Sep 2018, Kai-Heng Feng wrote:
> > >>
> > >>> 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?
> > >>
> > >>
> > >> Probably.
>
> Have you seen this thread:
> https://patchwork.ozlabs.org/cover/968924/
>
> and this one:
> https://patchwork.kernel.org/patch/10583229/

Ya!  It is the one.  And it is discussed in bugzilla
https://bugzilla.kernel.org/show_bug.cgi?id=201181
Now, the revert patch is submitted https://lkml.org/lkml/2018/9/27/224
However, still thanks for your information. :)

Regards,
Jian-Hong Pan

> ?
>
> > >
> > >
> > > Hopefully Jian-Hong can cook up a quirk table for the issue.
> >
> > Module r8169 gets nothing in the PCI BAR after system resumes which
> > makes MSI-X fail on some ASUS laptops equipped with RTL8106e chip.
> > https://www.spinics.net/lists/linux-pci/msg75598.html
> >
> > Actually, I am waiting for the patch "PCI: Reprogram bridge prefetch
> > registers on resume" being merged.
> > https://marc.info/?l=linux-pm&m=153680987814299&w=2
> >
> > It resolves the drivers which get nothing in PCI BAR after system resumes.
> >
> > After that, I can remove the falling back code of RTL8106e.
> >
> > Heiner, any comment?
> >
> > Regards,
> > Jian-Hong Pan
> >
> > >>
> > >>> 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
> > >>
> > >>
> > >> It's not because of that commit, really. There is a interrupt sent after
> > >> resume to the wrong vector for whatever reason. The MSI vector cannot be
> > >> masked it seems in the device, but the driver should quiescen the device
> > >> to
> > >> a point where it does not send interrupts.
> > >
> > >
> > > Understood.
> > >
> > >>
> > >>> If the device uses MSI-X instead of MSI, the issue doesn't happen because
> > >>> of
> > >>> reservation mode.
> > >>
> > >>
> > >> Reservation mode has absolutely nothing to do with that. What prevents the
> > >> issue is the fact that MSI-X can be masked by the IRQ core.
> > >
> > >
> > > So in this case I think keep the device using MSI-X is a better route, it's
> > > MSI-X capable anyway.
> > >
> > >>
> > >>> 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.
> > >>
> > >>
> > >> Suspend to idle works completely different and I don't see the BIOS at
> > >> fault here. it's more an issue of MSI not being maskable on that device,
> > >> which can't be fixed in BIOS or it's some half quiescened state which is
> > >> used when suspending and that's a pure driver issue.
> > >
> > >
> > > Understood.
> > > Thanks for all the info!
> > >
> > > Kai-Heng
> > >
> > >>
> > >> Thanks,
> > >>
> > >>         tglx
> > >
> > >
> > >
>
>
>
> --
> With Best Regards,
> Andy Shevchenko

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