of_property_match_string calls of_find_property to search for the
string property.
If the device node does not exist, of_find_property returns NULL, and
of_property_match_string returns -EINVAL, which is correct.
However, if the device node exists, but the property is not found,
of_find_property still returns NULL, but it will place -FDT_ERR_NOTFOUND
in the *lenp variable.
of_property_match_string does not use the lenp parameter, thus this error
case is being lost, and treated as if the node is NULL, and returns
-EINVAL, which is incorrect.
The callers of of_property_match_string treat the error differently if
the return value is -EINVAL or -ENOENT, e.g. in dwc3 driver:
ret = generic_phy_get_by_name(dev, "usb3-phy", &phy);
if (!ret) {
ret = generic_phy_init(&phy);
if (ret)
return ret;
} else if (ret != -ENOENT && ret != -ENODATA) {
debug("could not get phy (err %d)\n", ret);
return ret;
} else {
phy.dev = NULL;
}
So the caller drivers will just consider the property missing if -ENOENT
is returned, versus the case of -EINVAL, which means something else.
To fix this situation, changed the code to call the of_find_property
with the right third argument to catch this error code and treat it
accordingly.
Signed-off-by: Eugen Hristev <eugen.hris...@collabora.com>
---
drivers/core/of_access.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/core/of_access.c b/drivers/core/of_access.c
index 81a307992c01..57f10445b122 100644
--- a/drivers/core/of_access.c
+++ b/drivers/core/of_access.c
@@ -593,11 +593,14 @@ int of_read_u64(const struct device_node *np, const char
*propname, u64 *outp)
int of_property_match_string(const struct device_node *np, const char
*propname,
const char *string)
{
- const struct property *prop = of_find_property(np, propname, NULL);
+ int len = 0;
+ const struct property *prop = of_find_property(np, propname, &len);
size_t l;
int i;
const char *p, *end;
+ if (!prop && len == -FDT_ERR_NOTFOUND)
+ return -ENOENT;
if (!prop)
return -EINVAL;
if (!prop->value)
--
2.34.1
