Re: applesmc oops in 3.10/3.11

[Josh Boyer]

On Thu, Sep 26, 2013 at 2:34 AM, Henrik Rydberg <rydberg@xxxxxxxxxxx> wrote:
>> > > This suggests that initialization may be attempted more than once. The key cache
>> > > is allocated only once, but the number of keys is read for each attempt.
>> > >
>> > > No idea if that can happen, but if the number of keys can increase after
>> > > the first initialization attempt you would have an explanation for the crash.
>> >
>> > Good idea, and easy enough to test with the patch below.
>> >
>> Should we apply this patch even though it may not solve the specific problem ?
>
> Yes, why not - it certainly won't hurt. I am running it right now, so
> it is at least run-tested.
>
>> Again, not sure if the key count can change, but the current code is at the very
>> least inconsistent, as it keeps reading the key count without updating or
>> verifying the cache size.
>
> Yes - I agree that the error state is far-fetched, but it is hard to
> see any other logical explanation. There is of course always the
> possibility that the problem is somewhere else completely.
>
> Proper patch attached.
>
> Thanks,
> Henrik
>
> ---
>
> From dedefba9167913c46e1896ce0624e68ffe95d532 Mon Sep 17 00:00:00 2001
> From: Henrik Rydberg <rydberg@xxxxxxxxxxx>
> Date: Thu, 26 Sep 2013 08:33:16 +0200
> Subject: [PATCH] hwmon: (applesmc) Check key count before proceeding
>
> After reports from Chris and Josh Boyer of a rare crash in applesmc,
> Guenter pointed at the initialization problem fixed below. The patch
> has not been verified to fix the crash, but should be applied
> regardless.
>
> Reported-by: <jwboyer@xxxxxxxxxxxxxxxxx>
> Suggested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> Signed-off-by: Henrik Rydberg <rydberg@xxxxxxxxxxx>
> ---
>  drivers/hwmon/applesmc.c | 11 ++++++++++-
>  1 file changed, 10 insertions(+), 1 deletion(-)

Thanks for the quick reply.  I'll get this rolled into our kernels soon.

josh
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