lkml.org 
[lkml]   [2011]   [Apr]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [Stable-review] [12/28] x86, cpu: Clean up AMD erratum 400 workaround
    On Tue, 2011-04-19 at 22:06 -0700, Greg KH wrote:
    > On Wed, Apr 20, 2011 at 05:48:30AM +0100, Ben Hutchings wrote:
    > > On Tue, 2011-04-19 at 20:11 -0700, Greg KH wrote:
    > > > On Wed, Apr 20, 2011 at 03:17:42AM +0100, Ben Hutchings wrote:
    > > > > On Tue, 2011-04-19 at 19:01 -0700, Greg KH wrote:
    > > > > > On Wed, Apr 20, 2011 at 02:40:53AM +0100, Ben Hutchings wrote:
    > > > > > > On Tue, 2011-04-19 at 13:30 -0700, Greg KH wrote:
    > > > > > > > 2.6.32-longterm review patch. If anyone has any objections, please let us know.
    > > > > > > >
    > > > > > > > ------------------
    > > > > > > >
    > > > > > > > From: Hans Rosenfeld <hans.rosenfeld@amd.com>
    > > > > > > >
    > > > > > > > commit 9d8888c2a214aece2494a49e699a097c2ba9498b upstream.
    > > > > > > >
    > > > > > > > Remove check_c1e_idle() and use the new AMD errata checking framework
    > > > > > > > instead.
    > > > > > >
    > > > > > > Clean-up patches are generally not candidates for longterm updates.
    > > > > >
    > > > > > This was added because a follow-on patch required it.
    > > > >
    > > > > Ah yes, 'x86, AMD: Set ARAT feature on AMD processors' is using the same
    > > > > condition.
    > > > >
    > > > > Of course, that could have been backported by referring to the function
    > > > > that this removes, rather than pulling in a load of other changes with
    > > > > consequent risk of regressions.
    > > >
    > > > I prefer to take original patches for stable, it makes it easier in the
    > > > end.
    > >
    > > It makes what easier, when? What I see here is a bug fix that is much
    > > larger than necessary, with a consequent risk of regression that seems
    > > way out of proportion to the benefit. (What actually *is* the benefit
    > > of these AMD changes?) And we have had several serious regressions in
    > > the 2.6.32.y series recently, so I really don't think we are getting the
    > > trade-off right.
    >
    > We got a few new quirks added for AMD hardware platforms that fix
    > problems.

    Maybe, but I still haven't seen anyone explain what those problems are!

    > It took 3 patches to get there, yes, but now, as time goes
    > on, adding new ones is even easier as the .32 code matches the .39 code
    > in this area due to these patches being added.
    >
    > Now if you find problems in these, great, let me know and I will work to
    > resolve them.
    >
    > As for regressions, what are you referring to?

    These are the regressions I'm aware of in the last few updates:

    2.6.32.36: 'x86: Cleanup highmap after brk is concluded' broke
    hibernation on x86-64 and some x86-32 machines (reverted in .37)
    2.6.32.36: 'signal: Prevent rt_sigqueueinfo and rt_tgsigqueueinfo from
    spoofing the signal code' broke glibc aio (fixed in .37)
    2.6.32.34: powerpc kdump/kexec changes didn't compile on UP or 32-bit
    (fixed in .37)
    2.6.32.30: 'x86 quirk: Fix polarity for IRQ0 pin2 override on SB800
    systems' broke the revision check for other quirks (fixed in .34)
    2.6.32.29: 'USB: Prevent buggy hubs from crashing the USB stack' broke
    MUSB on BeagleBoards (still unfixed?)

    Ben.

    --
    Ben Hutchings
    Once a job is fouled up, anything done to improve it makes it worse.
    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2011-04-21 05:31    [W:0.041 / U:0.172 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site