On Thu, 22 May 2014 18:14:38 -0700, Frank Rowand <frowand.list@xxxxxxxxx> wrote: > On 5/21/2014 6:16 PM, Grant Likely wrote: > > On Tue, 20 May 2014 19:41:22 -0700, Frank Rowand <frowand.list@xxxxxxxxx> wrote: > >> On 5/18/2014 2:27 AM, Grant Likely wrote: > >>> On Fri, 16 May 2014 11:54:44 +0100, Grant Likely <grant.likely@xxxxxxxxxx> wrote: > >>>> On Thu, 15 May 2014 19:51:17 -0700, Frank Rowand <frowand.list@xxxxxxxxx> 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 <david.daney@xxxxxxxxxx> > >>>>>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx> > >>>>>> [grant.likely: Rework to not require allocating at runtime] > >>>>>> Acked-by: Rob Herring <robh@xxxxxxxxxx> > >>>>>> Signed-off-by: Grant Likely <grant.likely@xxxxxxxxxx> > >>>>>> --- > >>>>>> 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? > > I have not thought of a case where matching against a trailing '/' would > hurt anything. It just seemed better to be consistent in naming. > I've gone ahead and merged in the trailing '/' fix. It can be relaxed later if deemed important. g. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html