On Tue, Apr 22, 2014 at 06:25:25PM -0700, Frank Rowand wrote:
> Create some infrastructure to aid trouble shooting device tree related
> boot issues.
>
> Add a %driver_name file to each device tree node sysfs directory which has had
> a driver bound to it. This allows detecting device tree nodes which failed
> to be bound to any driver.
Why is this needed, shouldn't there already be a "driver" symlink in
sysfs for these devices when a driver binds to them? The rest of the
driver model works that way, why is of devices any different?
> Examples of using the %driver_name file (note that /proc/device-tree is a
> link to the base of the device tree sysfs tree):
>
>
> 1) To find list of device tree nodes with no driver:
>
> # A few false positives may be reported. For example,
> # node_full_path of "." is the board.
> #
> # output is: node_full_path compatible_string
> #
> cd /proc/device-tree
> for k in `find . -type d`; do
> if [[ -f ${k}/compatible && ! -f ${k}/%driver_name ]] ; then
> if [[ "`cat ${k}/compatible`" != "simple-bus" ]] ; then
> echo `echo ${k} | sed -e 's|./||'` `cat ${k}/compatible`
> fi
> fi
> done | sort
>
>
> 2) To find list of device tree nodes with a bound driver:
>
> # output is: node_full_path driver_name
> #
> cd /proc/device-tree
> for k in `find . -name %driver_name` ; do
> echo `echo ${k} | sed -e 's|./||' -e 's|/%driver_name$||'` `cat ${k}`
> done | sort
>
>
> 3) To find list of device tree nodes with a bound driver:
>
> # output is: driver_name node_full_path
> #
> cd /proc/device-tree
> for k in `find . -name %driver_name` ; do
> echo `cat ${k}` `echo ${k} | sed -e 's|./||' -e 's|/%driver_name$||'`
> done | sort
If we take this patch, these examples should be somewhere in the
documentation to make it easy for others.
> Signed-off-by: Frank Rowand <frank.rowand@xxxxxxxxxxxxxx>
Minor nit, your From: line doesn't match this signed-off-by: so
something has to change (or add a new From: line, like SubmittingPatches
decribes how to do.)
thanks,
greg k-h
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