[bugzilla-daemon@kernel.org: [Bug 216109] New: Steam Deck fails to boot when E820 entries clipped out of _CRS]

[bugzilla-daemon@kernel.org: [Bug 216109] New: Steam Deck fails to boot when E820 entries clipped out of _CRS]

[Bjorn Helgaas]

New regression in v5.19-rc1.

----- Forwarded message from bugzilla-daemon@kernel.org -----

Subject: [Bug 216109] New: Steam Deck fails to boot when E820 entries clipped
	out of _CRS

https://bugzilla.kernel.org/show_bug.cgi?id=216109

           Summary: Steam Deck fails to boot when E820 entries clipped out
                    of _CRS
    Kernel Version: v5.19

Guilherme G. Piccoli reported that v5.18 boots fine on Steam Deck, but
v5.19-rc1 does not.  He bisected it to 4c5e242d3e93 ("x86/PCI: Clip only host
bridge windows for E820 regions") [1].

A quirk similar to [2] that disables E820 clipping makes v5.19-rc1 work again.

The reason why v5.18 (which always does E820 clipping by default) works, while
v5.19-rc1 (which also does E820 clipping on this platform) does not has not
been explained yet.

[1] https://git.kernel.org/linus/4c5e242d3e93
[2] https://git.kernel.org/linus/d341838d776a

----- End forwarded message -----

Re: [bugzilla-daemon@kernel.org: [Bug 216109] New: Steam Deck fails to boot when E820 entries clipped out of _CRS]

[Hans de Goede]

Hi,

On 6/10/22 00:43, Bjorn Helgaas wrote:
> New regression in v5.19-rc1.
> 
> ----- Forwarded message from bugzilla-daemon@kernel.org -----
> 
> Subject: [Bug 216109] New: Steam Deck fails to boot when E820 entries clipped
> 	out of _CRS
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=216109
> 
>            Summary: Steam Deck fails to boot when E820 entries clipped out
>                     of _CRS
>     Kernel Version: v5.19
> 
> Guilherme G. Piccoli reported that v5.18 boots fine on Steam Deck, but
> v5.19-rc1 does not.  He bisected it to 4c5e242d3e93 ("x86/PCI: Clip only host
> bridge windows for E820 regions") [1].
> 
> A quirk similar to [2] that disables E820 clipping makes v5.19-rc1 work again.
> 
> The reason why v5.18 (which always does E820 clipping by default) works, while
> v5.19-rc1 (which also does E820 clipping on this platform) does not has not
> been explained yet.
> 
> [1] https://git.kernel.org/linus/4c5e242d3e93
> [2] https://git.kernel.org/linus/d341838d776a
> 
> ----- End forwarded message -----

I've added some analysis of the logs to the bug. Summary: I think we may
need to revert 4c5e242d3e93, this will be a non trivial revert moving
the pci_use_e820 check added in later commits to arch_remove_reservations().

See the bug for details and lets discuss this further in the bug.

In case we do eventually decide to go with a revert, I'll prepare
a revert later today and push it to:

https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Note I do NOT plan to merge this through the pdx86 tree, the reason
to put it there is to get the builders to play with it, since in the
past: https://lore.kernel.org/linux-pci/20211014183943.27717-2-hdegoede@redhat.com/
we had some build issues with the check inside arch_remove_reservations().

Regards,

Hans

Re: [bugzilla-daemon@kernel.org: [Bug 216109] New: Steam Deck fails to boot when E820 entries clipped out of _CRS]

[Thorsten Leemhuis]

[TLDR: I'm adding this regression report to the list of tracked
regressions; all text from me you find below is based on a few templates
paragraphs you might have encountered already already in similar form.]

Hi, this is your Linux kernel regression tracker.

On 10.06.22 00:43, Bjorn Helgaas wrote:
> New regression in v5.19-rc1.
> 
> ----- Forwarded message from bugzilla-daemon@kernel.org -----
> 
> Subject: [Bug 216109] New: Steam Deck fails to boot when E820 entries clipped
> 	out of _CRS
> 
> https://bugzilla.kernel.org/show_bug.cgi?id=216109
> 
>            Summary: Steam Deck fails to boot when E820 entries clipped out
>                     of _CRS
>     Kernel Version: v5.19
> 
> Guilherme G. Piccoli reported that v5.18 boots fine on Steam Deck, but
> v5.19-rc1 does not.  He bisected it to 4c5e242d3e93 ("x86/PCI: Clip only host
> bridge windows for E820 regions") [1].
>
> A quirk similar to [2] that disables E820 clipping makes v5.19-rc1 work again.
> 
> The reason why v5.18 (which always does E820 clipping by default) works, while
> v5.19-rc1 (which also does E820 clipping on this platform) does not has not
> been explained yet.
> 
> [1] https://git.kernel.org/linus/4c5e242d3e93
> [2] https://git.kernel.org/linus/d341838d776a

To be sure below issue doesn't fall through the cracks unnoticed, I'm
adding it to regzbot, my Linux kernel regression tracking bot:

#regzbot ^introduced 4c5e242d3e93
#regzbot title x86/PCI/e820:Steam Deck fails to boot when E820 entries
clipped out of _CRS
#regzbot ignore-activity
#regzbot link: https://bugzilla.kernel.org/show_bug.cgi?id=216109

This isn't a regression? This issue or a fix for it are already
discussed somewhere else? It was fixed already? You want to clarify when
the regression started to happen? Or point out I got the title or
something else totally wrong? Then just reply -- ideally with also
telling regzbot about it, as explained here:
https://linux-regtracking.leemhuis.info/tracked-regression/

Reminder for developers: When fixing the issue, add 'Link:' tags
pointing to the report (the mail this one replied to), as the kernel's
documentation call for; above page explains why this is important for
tracked regressions.

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I deal with a lot of
reports and sometimes miss something important when writing mails like
this. If that's the case here, don't hesitate to tell me in a public
reply, it's in everyone's interest to set the public record straight.

Re: [bugzilla-daemon@kernel.org: [Bug 216109] New: Steam Deck fails to boot when E820 entries clipped out of _CRS] #forregzbot

[Thorsten Leemhuis]

TWIMC: this mail is primarily send for documentation purposes and for
regzbot, my Linux kernel regression tracking bot. These mails usually
contain '#forregzbot' in the subject, to make them easy to spot and filter.

On 12.06.22 13:11, Thorsten Leemhuis wrote:

>> Subject: [Bug 216109] New: Steam Deck fails to boot when E820 entries clipped
>> 	out of _CRS
>>
>> https://bugzilla.kernel.org/show_bug.cgi?id=216109

#regzbot fixed-by: a2b36ffbf5b6

Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)

P.S.: As the Linux kernel's regression tracker I deal with a lot of
reports and sometimes miss something important when writing mails like
this. If that's the case here, don't hesitate to tell me in a public
reply, it's in everyone's interest to set the public record straight.