[FE training-materials-updates] Disable lockdep in the kernel configuration

[Thomas Petazzoni]

Repository : git://git.free-electrons.com/training-materials.git

On branch  : master
Link       : http://git.free-electrons.com/training-materials/commit/?id=832034a1d00f073b988db1b5c5700e46416a19fa

>---------------------------------------------------------------

commit 832034a1d00f073b988db1b5c5700e46416a19fa
Author: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
Date:   Thu May 30 16:30:06 2013 +0200

    Disable lockdep in the kernel configuration
    
    Tell people to disable lockdep, it shows some scary warnings when a
    JFFS2 root filesystem is used.
    
    Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>


>---------------------------------------------------------------

832034a1d00f073b988db1b5c5700e46416a19fa
 .../sysdev-kernel-cross-compiling.tex              |   19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/labs/sysdev-kernel-cross-compiling/sysdev-kernel-cross-compiling.tex b/labs/sysdev-kernel-cross-compiling/sysdev-kernel-cross-compiling.tex
index a111263..2a08f93 100644
--- a/labs/sysdev-kernel-cross-compiling/sysdev-kernel-cross-compiling.tex
+++ b/labs/sysdev-kernel-cross-compiling/sysdev-kernel-cross-compiling.tex
@@ -58,10 +58,21 @@ ready-made configuration.
 Don't hesitate to visualize the new settings by running
 \code{make xconfig} afterwards!
 
-As an example of configuration modification, let's change the kernel
-compression from Gzip to LZMA. This compression algorithm is far more
-efficient than Gzip, in terms of compression ratio, at the expense of
-a higher decompression time.
+In the kernel configuration :
+
+\begin{itemize}
+
+\item Make sure to disable \code{CONFIG_PROVE_LOCKING}. This option is
+  currently causing problems with the JFFS2 filesystem. This option is
+  in \code{Kernel Hacking} $\rightarrow$
+  \code{Lock debugging: prove locking correctness}.
+
+\item As an experiment, let's change the kernel compression from Gzip
+  to LZMA. This compression algorithm is far more efficient than Gzip,
+  in terms of compression ratio, at the expense of a higher
+  decompression time.
+
+\end{itemize}
 
 \section{Cross compiling}