[PATCH v5] of/promtree: allow DT device matching by fixing 'name' brokenness

Grant Likely
2011-02-24T17:04:46Z

From: Andres Salomon <dilinger@queued.net>

Commit e2f2a93b, "of/promtree: add package-to-path support to pdt"
changed dp->name from using the 'name' property to using
package-to-path. This fixed /proc/device-tree creation by eliminating
conflicts between names (the 'name' property provides names like
'battery', whereas package-to-path provides names like
'/foo/bar/battery@0', which we stripped to 'battery@0'). However, it
also breaks of_device_id table matching.

The fix that we _really_ wanted was to keep dp->name based upon
the name property ('battery'), but based dp->full_name upon
package-to-path ('battery@0'). This patch does just that.

This changes all users (except SPARC) of promtree to use the full
result from package-to-path for full_name, rather than stripping the
directory out. In practice, the strings end up being exactly the
same; this change saves time, code, and memory.

SPARC continues to use the existing build_path_component() code.

v2: combine two patches and revert of_pdt_node_name to original version
v3: use dp->phandle instead of passing around node
v4: warn/bail out for non-sparc archs if pkg2path is not set
v5: split of_pdt_build_full_name into sparc & non-sparc versions
BUG() when pkg2path doesn't work.

Signed-off-by: Andres Salomon <dilinger@queued.net>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
---

Hi Andres,

This is what I think the patch should really look like. The
of_pdt_node_name() stuff really doesn't make sense to keep around
because what we *really* care about is the full name, not the path
component name. Therefore I reorganized it so SPARC continues to use
it's build_path_component() to build up the full path; but everyone
else *must* provide a working mechanism to obtain the full path; be it
an actual call to OFW pkg2path, or something else.

Please take a look at let me know what you think.

g.

drivers/of/pdt.c | 110 ++++++++++++++++++++----------------------------------
1 files changed, 40 insertions(+), 70 deletions(-)

diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
index 28295d0..ab54819 100644
--- a/drivers/of/pdt.c
+++ b/drivers/of/pdt.c
@@ -36,19 +36,53 @@ unsigned int of_pdt_unique_id __initdata;
(p)->unique_id = of_pdt_unique_id++; \
} while (0)

-static inline const char *of_pdt_node_name(struct device_node *dp)
+static char * __init of_pdt_build_full_name(struct device_node *dp)
{
- return dp->path_component_name;
+ int len, ourlen, plen;
+ char *n;
+
+ dp->path_component_name = build_path_component(dp);
+
+ plen = strlen(dp->parent->full_name);
+ ourlen = strlen(dp->path_component_name);
+ len = ourlen + plen + 2;
+
+ n = prom_early_alloc(len);
+ strcpy(n, dp->parent->full_name);
+ if (!of_node_is_root(dp->parent)) {
+ strcpy(n + plen, "/");
+ plen++;
+ }
+ strcpy(n + plen, dp->path_component_name);
+
+ return n;
}

-#else
+#else /* CONFIG_SPARC */

static inline void of_pdt_incr_unique_id(void *p) { }
static inline void irq_trans_init(struct device_node *dp) { }

-static inline const char *of_pdt_node_name(struct device_node *dp)
+static char * __init of_pdt_build_full_name(struct device_node *dp)
{
- return dp->name;
+ char *buf;
+ int len;
+
+ if (!of_pdt_prom_ops->pkg2path)
+ BUG();
+
+ if (of_pdt_prom_ops->pkg2path(dp->phandle, buf, 0, &len))
+ BUG();
+
+ buf = prom_early_alloc(len + 1);
+ if (!buf)
+ BUG();
+
+ if (of_pdt_prom_ops->pkg2path(dp->phandle, buf, len, &len)) {
+ pr_err("%s: package-to-path failed\n", __func__);
+ BUG();
+ }
+ return buf;
}

#endif /* !CONFIG_SPARC */
@@ -132,47 +166,6 @@ static char * __init of_pdt_get_one_property(phandle node, const char *name)
return buf;
}

-static char * __init of_pdt_try_pkg2path(phandle node)
-{
- char *res, *buf = NULL;
- int len;
-
- if (!of_pdt_prom_ops->pkg2path)
- return NULL;
-
- if (of_pdt_prom_ops->pkg2path(node, buf, 0, &len))
- return NULL;
- buf = prom_early_alloc(len + 1);
- if (of_pdt_prom_ops->pkg2path(node, buf, len, &len)) {
- pr_err("%s: package-to-path failed\n", __func__);
- return NULL;
- }
-
- res = strrchr(buf, '/');
- if (!res) {
- pr_err("%s: couldn't find / in %s\n", __func__, buf);
- return NULL;
- }
- return res+1;
-}
-
-/*
- * When fetching the node's name, first try using package-to-path; if
- * that fails (either because the arch hasn't supplied a PROM callback,
- * or some other random failure), fall back to just looking at the node's
- * 'name' property.
- */
-static char * __init of_pdt_build_name(phandle node)
-{
- char *buf;
-
- buf = of_pdt_try_pkg2path(node);
- if (!buf)
- buf = of_pdt_get_one_property(node, "name");
-
- return buf;
-}
-
static struct device_node * __init of_pdt_create_node(phandle node,
struct device_node *parent)
{
@@ -187,7 +180,7 @@ static struct device_node * __init of_pdt_create_node(phandle node,

kref_init(&dp->kref);

- dp->name = of_pdt_build_name(node);
+ dp->name = of_pdt_get_one_property(node, "name");
dp->type = of_pdt_get_one_property(node, "device_type");
dp->phandle = node;

@@ -198,26 +191,6 @@ static struct device_node * __init of_pdt_create_node(phandle node,
return dp;
}

-static char * __init of_pdt_build_full_name(struct device_node *dp)
-{
- int len, ourlen, plen;
- char *n;
-
- plen = strlen(dp->parent->full_name);
- ourlen = strlen(of_pdt_node_name(dp));
- len = ourlen + plen + 2;
-
- n = prom_early_alloc(len);
- strcpy(n, dp->parent->full_name);
- if (!of_node_is_root(dp->parent)) {
- strcpy(n + plen, "/");
- plen++;
- }
- strcpy(n + plen, of_pdt_node_name(dp));
-
- return n;
-}
-
static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
phandle node,
struct device_node ***nextp)
@@ -240,9 +213,6 @@ static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
*(*nextp) = dp;
*nextp = &dp->allnext;

-#if defined(CONFIG_SPARC)
- dp->path_component_name = build_path_component(dp);
-#endif
dp->full_name = of_pdt_build_full_name(dp);

dp->child = of_pdt_build_tree(dp,