On 3/21/2019 1:25 AM, Frank Rowand wrote:
On 3/20/19 3:49 AM, Mukesh Ojha wrote:
Existing check of `fn` against NULL inside OF match table
is redundant. Remove the check.
Signed-off-by: Mukesh Ojha <mojha@xxxxxxxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Frank Rowand <frowand.list@xxxxxxxxx>
Cc: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
Cc: devicetree@xxxxxxxxxxxxxxx
---
include/linux/of.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/linux/of.h b/include/linux/of.h
index e240992..b86c00a 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -1283,13 +1283,13 @@ static inline int of_get_available_child_count(const struct device_node *np)
static const struct of_device_id __of_table_##name \
__used __section(__##table##_of_table) \
= { .compatible = compat, \
- .data = (fn == (fn_type)NULL) ? fn : fn }
+ .data = fn }
#else
#define _OF_DECLARE(table, name, compat, fn, fn_type) \
static const struct of_device_id __of_table_##name \
__attribute__((unused)) \
= { .compatible = compat, \
- .data = (fn == (fn_type)NULL) ? fn : fn }
+ .data = fn }
#endif
typedef int (*of_init_fn_2)(struct device_node *, struct device_node *);
The check is not redundant and does serve a purpose.
The purpose is not very obvious on the surface, but it is checking that
the function fn() is of the proper type.
Frank,
Thanks for taking out time to explain the stuff, Yeah some miscellaneous
driver can do this type of mistake.
-Mukesh
An example of a compiler warning with a bad function type is created
by applying the following patch:
drivers/of/unittest.c:62:1: warning: comparison of distinct pointer types lacks a cast [enabled by default]
Note that you need to have CONFIG_UNITTEST enabled to compile unittest.c.
Line 62 is
OF_DECLARE_1(__unittest_of_table, unittest_setup_2_bad, "unittest_compat",
---
drivers/of/unittest.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
Index: b/drivers/of/unittest.c
===================================================================
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -45,6 +45,23 @@ static struct unittest_results {
failed; \
})
+struct of_device_id __unittest_of_table;
+
+static void __init unittest_setup_1_good(struct device_node *np)
+{
+}
+
+static void __init unittest_setup_2_bad(struct device_node *np_1,
+ struct device_node *np_2)
+{
+}
+
+OF_DECLARE_1(__unittest_of_table, unittest_setup_1_good, "unittest_compat",
+ unittest_setup_1_good);
+
+OF_DECLARE_1(__unittest_of_table, unittest_setup_2_bad, "unittest_compat",
+ unittest_setup_2_bad);
+
static void __init of_unittest_find_node_by_name(void)
{
struct device_node *np;
