On Tue, 20 May 2014 19:41:22 -0700, Frank Rowand <[email protected]> wrote: > On 5/18/2014 2:27 AM, Grant Likely wrote: > > On Fri, 16 May 2014 11:54:44 +0100, Grant Likely <[email protected]> > > wrote: > >> On Thu, 15 May 2014 19:51:17 -0700, Frank Rowand <[email protected]> > >> wrote: > >>> On 5/13/2014 7:58 AM, Grant Likely wrote: > >>>> Make of_find_node_by_path() handle aliases as prefixes. To make this > >>>> work the name search is refactored to search by path component instead > >>>> of by full string. This should be a more efficient search, and it makes > >>>> it possible to start a search at a subnode of a tree. > >>>> > >>>> Signed-off-by: David Daney <[email protected]> > >>>> Signed-off-by: Pantelis Antoniou <[email protected]> > >>>> [grant.likely: Rework to not require allocating at runtime] > >>>> Acked-by: Rob Herring <[email protected]> > >>>> Signed-off-by: Grant Likely <[email protected]> > >>>> --- > >>>> drivers/of/base.c | 60 > >>>> +++++++++++++++++++++++++++++++++++++++++++++++++++---- > >>>> 1 file changed, 56 insertions(+), 4 deletions(-) > >>>> > >>>> diff --git a/drivers/of/base.c b/drivers/of/base.c > >>>> index 6e240698353b..60089b9a3014 100644 > >>>> --- a/drivers/of/base.c > >>>> +++ b/drivers/of/base.c > >>>> @@ -771,9 +771,38 @@ struct device_node *of_get_child_by_name(const > >>>> struct device_node *node, > >>>> } > >>>> EXPORT_SYMBOL(of_get_child_by_name); > >>>> > >>>> +static struct device_node *__of_find_node_by_path(struct device_node > >>>> *parent, > >>>> + const char *path) > >>>> +{ > >>>> + struct device_node *child; > >>>> + int len = strchrnul(path, '/') - path; > >>>> + > >>>> + if (!len) > >>>> + return parent; > >>> > >>> (!len) is true if the the final character of the path passed into > >>> of_find_node_by_path() > >>> was "/". Strictly speaking, ->full_name will never end with "/", so the > >>> return value > >>> should be NULL, indicating that the match fails. > >> > >> Ah, good catch. I should add a test case for that. > > > > In my testing this looks okay. The while loop that calls into > > __of_find_node_by_path() looks like this: > > > > while (np && *path == '/') { > > path++; /* Increment past '/' delimiter */ > > np = __of_find_node_by_path(np, path); > > path = strchrnul(path, '/'); > > } > > > > If the path ends with a '/', then the loop will go around one more time. > > The pointer will be incremented to point at the null character and len > > will be null because strchrnul() will point at the last item. > > Yes, that was my point. The old version of of_find_node_by_path() would not > find a match if the path ended with a "/" (unless the full path was "/"). > This patch series changes the behavior to be a match. > > I will reply to this email with an additional patch that restores the > original behavior. > > If you move the additional test cases you provide below and the test cases > in patch 3 to the beginning of the series, you can see the before and after > behavior of adding patch 1 and patch 2.
Ah, I see. That raises the question about what the behaviour /should/ be. Off the top of my head, matching against a trailing '/' seems to be okay. Are there situations that you see or can think of where matching would be the wrong thing to do? g. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
