| Message ID | 20140518092730.109AAC40B8A@trevor.secretlab.ca |
|---|---|
| State | New |
| Headers | show |
On 5/18/2014 2:27 AM, Grant Likely wrote: > On Fri, 16 May 2014 11:54:44 +0100, Grant Likely <grant.likely@linaro.org> wrote: >> On Thu, 15 May 2014 19:51:17 -0700, Frank Rowand <frowand.list@gmail.com> 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@cavium.com> >>>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> >>>> [grant.likely: Rework to not require allocating at runtime] >>>> Acked-by: Rob Herring <robh@kernel.org> >>>> Signed-off-by: Grant Likely <grant.likely@linaro.org> >>>> --- >>>> 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. > > I've added a couple of test cases to make sure it works correctly: > > diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c > index a9d00e8c17ea..10900b18fc06 100644 > --- a/drivers/of/selftest.c > +++ b/drivers/of/selftest.c > @@ -40,6 +40,12 @@ static void __init of_selftest_find_node_by_name(void) > "find /testcase-data failed\n"); > of_node_put(np); > > + /* Test if trailing '/' works */ > + np = of_find_node_by_path("/testcase-data/"); > + selftest(np && !strcmp("/testcase-data", np->full_name), > + "find /testcase-data/ failed\n"); > + of_node_put(np); > + > np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a"); > selftest(np && !strcmp("/testcase-data/phandle-tests/consumer-a", np->full_name), > "find /testcase-data/phandle-tests/consumer-a failed\n"); > @@ -50,6 +56,12 @@ static void __init of_selftest_find_node_by_name(void) > "find testcase-alias failed\n"); > of_node_put(np); > > + /* Test if trailing '/' works on aliases */ > + np = of_find_node_by_path("testcase-alias/"); > + selftest(np && !strcmp("/testcase-data", np->full_name), > + "find testcase-alias/ failed\n"); > + of_node_put(np); > + > np = of_find_node_by_path("testcase-alias/phandle-tests/consumer-a"); > selftest(np && !strcmp("/testcase-data/phandle-tests/consumer-a", np->full_name), > "find testcase-alias/phandle-tests/consumer-a failed\n"); > > g. > > >> >>> >>>> + >>>> + for_each_child_of_node(parent, child) { >>>> + const char *name = strrchr(child->full_name, '/'); >>>> + if (WARN(!name, "malformed device_node %s\n", child->full_name)) >>>> + continue; >>>> + name++; < snip > -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, 20 May 2014 19:41:22 -0700, Frank Rowand <frowand.list@gmail.com> wrote: > On 5/18/2014 2:27 AM, Grant Likely wrote: > > On Fri, 16 May 2014 11:54:44 +0100, Grant Likely <grant.likely@linaro.org> wrote: > >> On Thu, 15 May 2014 19:51:17 -0700, Frank Rowand <frowand.list@gmail.com> 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@cavium.com> > >>>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> > >>>> [grant.likely: Rework to not require allocating at runtime] > >>>> Acked-by: Rob Herring <robh@kernel.org> > >>>> Signed-off-by: Grant Likely <grant.likely@linaro.org> > >>>> --- > >>>> 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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
On 5/21/2014 6:16 PM, Grant Likely wrote: > On Tue, 20 May 2014 19:41:22 -0700, Frank Rowand <frowand.list@gmail.com> wrote: >> On 5/18/2014 2:27 AM, Grant Likely wrote: >>> On Fri, 16 May 2014 11:54:44 +0100, Grant Likely <grant.likely@linaro.org> wrote: >>>> On Thu, 15 May 2014 19:51:17 -0700, Frank Rowand <frowand.list@gmail.com> 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@cavium.com> >>>>>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> >>>>>> [grant.likely: Rework to not require allocating at runtime] >>>>>> Acked-by: Rob Herring <robh@kernel.org> >>>>>> Signed-off-by: Grant Likely <grant.likely@linaro.org> >>>>>> --- >>>>>> 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. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 22 May 2014 18:14:38 -0700, Frank Rowand <frowand.list@gmail.com> wrote: > On 5/21/2014 6:16 PM, Grant Likely wrote: > > On Tue, 20 May 2014 19:41:22 -0700, Frank Rowand <frowand.list@gmail.com> wrote: > >> On 5/18/2014 2:27 AM, Grant Likely wrote: > >>> On Fri, 16 May 2014 11:54:44 +0100, Grant Likely <grant.likely@linaro.org> wrote: > >>>> On Thu, 15 May 2014 19:51:17 -0700, Frank Rowand <frowand.list@gmail.com> 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@cavium.com> > >>>>>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> > >>>>>> [grant.likely: Rework to not require allocating at runtime] > >>>>>> Acked-by: Rob Herring <robh@kernel.org> > >>>>>> Signed-off-by: Grant Likely <grant.likely@linaro.org> > >>>>>> --- > >>>>>> 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 linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c index a9d00e8c17ea..10900b18fc06 100644 --- a/drivers/of/selftest.c +++ b/drivers/of/selftest.c @@ -40,6 +40,12 @@ static void __init of_selftest_find_node_by_name(void) "find /testcase-data failed\n"); of_node_put(np); + /* Test if trailing '/' works */ + np = of_find_node_by_path("/testcase-data/"); + selftest(np && !strcmp("/testcase-data", np->full_name), + "find /testcase-data/ failed\n"); + of_node_put(np); + np = of_find_node_by_path("/testcase-data/phandle-tests/consumer-a"); selftest(np && !strcmp("/testcase-data/phandle-tests/consumer-a", np->full_name), "find /testcase-data/phandle-tests/consumer-a failed\n"); @@ -50,6 +56,12 @@ static void __init of_selftest_find_node_by_name(void) "find testcase-alias failed\n"); of_node_put(np); + /* Test if trailing '/' works on aliases */ + np = of_find_node_by_path("testcase-alias/"); + selftest(np && !strcmp("/testcase-data", np->full_name), + "find testcase-alias/ failed\n"); + of_node_put(np); + np = of_find_node_by_path("testcase-alias/phandle-tests/consumer-a"); selftest(np && !strcmp("/testcase-data/phandle-tests/consumer-a", np->full_name), "find testcase-alias/phandle-tests/consumer-a failed\n");