Re: [PATCH v4 00/10] Introduce SMT level and add PowerPC support

[Zhang, Rui]

Hi, Thomas,

On Fri, 2023-07-28 at 09:40 +0200, Thomas Gleixner wrote:
> Rui!
> 
> On Sun, Jul 09 2023 at 15:25, Rui Zhang wrote:
> > I ran into a boot hang regression with latest upstream code, and it
> > took me a while to bisect the offending commit and workaround it.
> 
> Where is the bug report and the analysis? And what's the workaround?

As it is an iwlwifi regression, I didn't paste the link here.

The regression was reported at
https://lore.kernel.org/all/b533071f38804247f06da9e52a04f15cce7a3836.camel@xxxxxxxxx/

And it was fixed later by below commit in 6.5-rc2.

thanks,
rui

commit 12a89f0177092dbc2a1cb1d05a9790adbcea2309
Author:     Johannes Berg <johannes.berg@xxxxxxxxx>
AuthorDate: Mon Jul 10 16:50:39 2023 +0200
Commit:     Jakub Kicinski <kuba@xxxxxxxxxx>
CommitDate: Tue Jul 11 20:26:06 2023 -0700

    wifi: iwlwifi: remove 'use_tfh' config to fix crash
    
    This is equivalent to 'gen2', and it was always confusing to have
    two identical config entries. The split config patch actually had
    been originally developed after removing 'use_tfh" and didn't add
    the use_tfh in the new configs as they'd later been copied to the
    new files. Thus the easiest way to fix the init crash here now is
    to just remove use_tfh (which is erroneously unset in most of the
    configs now) and use 'gen2' in the code instead.
    
    There's possibly still an unwind error in iwl_txq_gen2_init() as
    it crashes if TXQ 0 fails to initialize, but we can deal with it
    later since the original failure is due to the use_tfh confusion.
    
    Tested-by: Xi Ruoyao <xry111@xxxxxxxxxxx>
    Reported-and-tested-by: Niklāvs Koļesņikovs
<pinkflames.linux@xxxxxxxxx>
    Reported-and-tested-by: Jeff Chua <jeff.chua.linux@xxxxxxxxx>
    Reported-and-tested-by: Zhang Rui <rui.zhang@xxxxxxxxx>
    Link: https://bugzilla.kernel.org/show_bug.cgi?id=217622
    Link:
https://lore.kernel.org/all/9274d9bd3d080a457649ff5addcc1726f08ef5b2.camel@xxxxxxxxxxx/
    Link:
https://lore.kernel.org/all/CAAJw_Zug6VCS5ZqTWaFSr9sd85k%3DtyPm9DEE%2BmV%3DAKoECZM%2BsQ@xxxxxxxxxxxxxx/
    Fixes: 19898ce9cf8a ("wifi: iwlwifi: split 22000.c into multiple
files")
    Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
    Link:
https://lore.kernel.org/r/20230710145038.84186-2-johannes@xxxxxxxxxxxxxxxx
    Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>

> 
> Thanks,
> 
>         tglx