linux-kernel - Re: [BUG BISECTED FAILED] Phenom microcode revision mis-identified

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Message-ID: <20131229201906.GR19878@titan.lakedaemon.net>
Date:	Sun, 29 Dec 2013 15:19:06 -0500
From:	Jason Cooper <jason@...edaemon.net>
To:	Gene Heskett <gheskett@...v.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: [BUG BISECTED FAILED] Phenom microcode revision mis-identified

On Sun, Dec 29, 2013 at 02:49:16PM -0500, Gene Heskett wrote:
> On Sunday 29 December 2013, Jason Cooper wrote:
> >On Sun, Dec 29, 2013 at 12:47:02PM -0500, Gene Heskett wrote:
> >> On Sunday 29 December 2013, Gene Heskett wrote:
> >> >Resend, incorrect subject line
> >> >
> >> >Here is the copy/paste of the final git bisect bad report:
> >> >
> >> >First, the reason for the bisect:
> >> >gene@...ote:~/linux-stable$ dmesg | grep -A2 microcode
> >> >[    0.518304] microcode: CPU0: patch_level=0x01000065
> >> >[    0.518396] microcode: CPU1: patch_level=0x01000065
> >> >[    0.518498] microcode: CPU2: patch_level=0x01000065
> >> >[    0.518593] microcode: CPU3: patch_level=0x01000065
> >> >[    0.518745] microcode: Microcode Update Driver: v2.00
> >> ><tigran@...azian.fsnet.co.uk>, Peter Oruba
> >> >
> >> >The output above should have in each cpu case, a second, or final line
> >> >showing a patch level 0x0100083 in all cases.
> >> >This failure is on an AMD phenom 9550 equipt machine.
> >> >
> >> >I can and have built from the tarball pull, a 3.8.2 which does work
> >> >correctly.  The tarball build of 3.8.3 fails as above, and a tarball
> >> >build of 3.12.6 still fails.
> >> >
> >> >gene@...ote:~/linux-stable$ git bisect bad
> >> >908e88f285b909011dc7dbce5abaacf123f2f68d is the first bad commit
> >> >commit 908e88f285b909011dc7dbce5abaacf123f2f68d
> >> >Author: Russell King <rmk+kernel@....linux.org.uk>
> >> >Date:   Mon Feb 25 16:09:12 2013 +0000
> >> >
> >> >I'll next do a "git checkout v3.8.2" to double check that it works.
> >
> >Please re-read the manpage for git bisect, particularly the section
> >"Basic bisect commands".  You need to keep repeating building and
> >booting the kernel, execute 'git bisect [good|bad]', as git bisect
> >checks out different commits to try.  Depending on the number of
> >commits, it can take 7 to 10 iterations before it nails it down to the
> >bad commit.
> >
> >$ git log --oneline v3.8.2..v3.8.3 | wc -l
> >103
> >
> >So you started at v3.8.3, said v3.8.2 is good.  git bisect will then
> >checkout a commit in the middle (of the 103 commits to choose from).  You
> >need to build that kernel, boot it, and see if the error occurs.  Then,
> >type 'git bisect [bad|good]' depending on what happened.  When that
> >command returns, it has checked out a different commit between v3.8.2
> >and v3.8.3.  Build, boot, and run 'git bisect [good|bad]' depending on
> >if the patch_level was reported properly.  Repeat until it reports
> >nothing left to test.
> >
> >> FWIW, a git checkout v3.8.2  also fails, so next I'll move my working
> >> tarball build .configs into that tree & see if it works.
> >
> >If the config you started with worked for v3.8.2 and didn't for v3.8.3,
> >keep using it.
> >
> >> This is getting stranger, a checkout v3.8.2 is supposed to match the
> >> tarball I got from kernel.org isn't it?
> >
> >Yes, see above.  As soon as you started the bisection process, you were
> >no longer on version 3.8.2 or 3.8.3, but somewhere in between.  That's
> >what's supposed to happen.
> >
> >Once you run enough iterations to get nothing left to test, record the
> >commit it identified, and run 'git bisect reset'.
> I did do that, the above report was the final of about 8 or 9 reboots after 
> telling it each time "git bisect bad".

I'm not trying to insult you, but just to be clear: After each reboot,
was the patch_level reported wrong?  If it was correct, you needed to
run 'git bisect good' instead.  I can't think of any other reason why it
would finger the commit above.

> These will all be 32 bit PAE kernels though as I don't know how to convert 
> it to 64 bit when a make xconfig doesn't give me that option.

Ahhh, then you should start with i386_defconfig.  You can see the full
list at arch/x86/configs/.  I assumed you were running 64bit, my fault.

thx,

Jason.
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