Subject: How to quickly resolve the IOMMU regression that currently plagues a lot of people in 5.19.y

[resend with proper subject, sorry for the noise]

[note to self: don't get distracted when writing the subject]

On 21.09.22 08:53, Thorsten Leemhuis wrote:
> Hi Greg! As you likely heard already, 5.19.9 introduced a regression
> that breaks Thunderbolt and USB-C docks (and apparently Wifi in some
> cases as well) on quite a few (many?) modern systems. It's one of those
> problems where I think "hey, we ideally should fix this in stable as
> fast as possible" we briefly talked about last week on the LPC hallways.
> That made me wonder how to actually archive that in this particular case
> while keeping all involved parties happy and not skipping any CI testing
> queues considered important.
>
> FWIW, here are a few few reports about the issue (I assume there are
> some for Arch Linux and openSUSE Tumbleweed as well, but didn't check).
>
> https://lore.kernel.org/linux-iommu/[email protected]/
> https://bugzilla.kernel.org/show_bug.cgi?id=216497
> https://bugzilla.redhat.com/show_bug.cgi?id=2128458
> https://bugzilla.redhat.com/show_bug.cgi?id=2127753
>
> A revert of the culprit (9cd4f1434479f ("iommu/vt-d: Fix possible
> recursive locking in intel_iommu_init()"); in 5.19.y it's 9516acba29e3)
> for mainline is here:
> https://lore.kernel.org/lkml/[email protected]/
>
> A few hours ago the revert was queued to get send to Joerg:
> https://lore.kernel.org/linux-iommu/[email protected]/
>
> I fear it could easily take another week to get this fixed in stable
> depending on how fast the patch makes it to mainline and the timing of
> the next 5.19.y release and its -rc phase. That to me sounds like way
> too long for a problem like this that apparently plagues quite a few
> people.
>
> That made me wonder: would you in cases like this be willing to start
> the -rc phase for a interim 5.19.y release with just that revert while
> it's still heading towards mainline? Then the CI systems that test
> stable -rcs could chew on things already; and the new stable release
> could go out right after the revert landed in mainline (unless the
> testing finds any problems, of course).
>
> Ciao, Thorsten
>
>


2022-09-21 08:52:18

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: How to quickly resolve the IOMMU regression that currently plagues a lot of people in 5.19.y

On Wed, Sep 21, 2022 at 10:19:10AM +0200, Joerg Roedel wrote:
> Hi Thorsten,
>
> On Wed, Sep 21, 2022 at 09:15:17AM +0200, Thorsten Leemhuis wrote:
> > [resend with proper subject, sorry for the noise]
>
> Thanks for the noise :) I will queue the fix today and send it upstream.

Great, thanks for doing this.

greg k-h

2022-09-21 09:08:39

by Joerg Roedel

[permalink] [raw]
Subject: Re: How to quickly resolve the IOMMU regression that currently plagues a lot of people in 5.19.y

Hi Thorsten,

On Wed, Sep 21, 2022 at 09:15:17AM +0200, Thorsten Leemhuis wrote:
> [resend with proper subject, sorry for the noise]

Thanks for the noise :) I will queue the fix today and send it upstream.

Regards,

Joerg

2022-09-21 16:45:59

by Linus Torvalds

[permalink] [raw]
Subject: Re: How to quickly resolve the IOMMU regression that currently plagues a lot of people in 5.19.y

On Wed, Sep 21, 2022 at 1:19 AM Joerg Roedel <[email protected]> wrote:
>
> Thanks for the noise :) I will queue the fix today and send it upstream.

.. and it's in my tree now.

Linus

2022-09-21 18:04:41

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: How to quickly resolve the IOMMU regression that currently plagues a lot of people in 5.19.y

On Wed, Sep 21, 2022 at 09:15:12AM -0700, Linus Torvalds wrote:
> On Wed, Sep 21, 2022 at 1:19 AM Joerg Roedel <[email protected]> wrote:
> >
> > Thanks for the noise :) I will queue the fix today and send it upstream.
>
> .. and it's in my tree now.

And now added to the next 5.19-rc release that is out for review now.

thanks for the quick response everyone,

greg k-h