Re: applesmc oops in 3.10/3.11

[Guenter Roeck <linux@roeck-us.net>]

On Mon, Oct 07, 2013 at 05:46:55PM -0600, Chris Murphy wrote:
> 
> On Oct 7, 2013, at 5:42 PM, Guenter Roeck <linux@roeck-us.net> wrote:
> 
> > On 10/02/2013 10:24 AM, Henrik Rydberg wrote:
> > 
> >>> From 4451da32414080bd0563ee9e061f19bf90463cc5 Mon Sep 17 00:00:00 2001
> >> From: Henrik Rydberg <rydberg@euromail.se>
> >> Date: Wed, 2 Oct 2013 19:15:03 +0200
> >> Subject: [PATCH] applesmc remedy take 2
> >> 
> >> Conjectured problem: there are remnant bytes ready on the data line
> >> which corrupts the read after a failure.
> >> 
> >> Remedy: assuming bit0 is the read valid line, try to flush it before
> >> starting a new command.
> >> 
> >> Tests by Chris suggests reading the status is enough for the problem
> >> to go away, which is consistent with a change in the SMC interface,
> >> where the number of bytes to read is no longer specified, but found
> >> out by reading until end of data.
> >> 
> >> Tested on a MacBookAir3,1, but the original problem has not been
> >> reproduced.
> > 
> > So, what should we do with this patch ? Apply it ?
> 
> So far I'm getting nothing on the original machine. As of today it's applied as the last patch on 3.12.0-0.rc4.git0.1.fc20.x86_64. Unfortunately at the moment I'm a bit too dense to figure out how to get a new kernel applied to an existing live package so I can try this on a USB stick. While maybe unrelated, the oops was occurring at least 4x as often booted from USB stick media than HDD.
> 

Seems to me we should apply it.

Henrik,

what do you think ? Did you have time for additional testing ?
If you think we should apply it, please send me a signed patch.

Thanks,
Guenter