lib: utils/fdt: Respect compatible string fallback priority

When matching drivers to DT nodes, always match all drivers against the
first compatible string before considering fallback compatible strings.
This ensures the most specific match is always selected, regardless of
the order of the drivers or match structures, as long as no compatible
string appears in multiple match structures.

Fixes: 1ccc52c427 ("lib: utils/fdt: Add helpers for generic driver initialization")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
This commit is contained in:
Samuel Holland
2025-02-19 12:42:51 -08:00
committed by Anup Patel
parent b2e8e6986d
commit 0ffe265fd9

View File

@@ -15,39 +15,43 @@ int fdt_driver_init_by_offset(const void *fdt, int nodeoff,
{
const struct fdt_driver *driver;
const struct fdt_match *match;
const void *prop;
int len, rc;
int compat_len, prop_len, rc;
const char *compat_str;
if (!fdt_node_is_enabled(fdt, nodeoff))
return SBI_ENODEV;
prop = fdt_getprop(fdt, nodeoff, "compatible", &len);
if (!prop)
compat_str = fdt_getprop(fdt, nodeoff, "compatible", &prop_len);
if (!compat_str)
return SBI_ENODEV;
while ((driver = *drivers++)) {
for (match = driver->match_table; match->compatible; match++) {
if (!fdt_stringlist_contains(prop, len, match->compatible))
continue;
while ((compat_len = strnlen(compat_str, prop_len) + 1) <= prop_len) {
for (int i = 0; (driver = drivers[i]); i++)
for (match = driver->match_table; match->compatible; match++)
if (!memcmp(match->compatible, compat_str, compat_len))
goto found;
if (driver->experimental)
sbi_printf("WARNING: %s driver is experimental and may change\n",
match->compatible);
rc = driver->init(fdt, nodeoff, match);
if (rc < 0) {
const char *name;
name = fdt_get_name(fdt, nodeoff, NULL);
sbi_printf("%s: %s (%s) init failed: %d\n",
__func__, name, match->compatible, rc);
}
return rc;
}
compat_str += compat_len;
prop_len -= compat_len;
}
return SBI_ENODEV;
found:
if (driver->experimental)
sbi_printf("WARNING: %s driver is experimental and may change\n",
match->compatible);
rc = driver->init(fdt, nodeoff, match);
if (rc < 0) {
const char *name;
name = fdt_get_name(fdt, nodeoff, NULL);
sbi_printf("%s: %s (%s) init failed: %d\n",
__func__, name, match->compatible, rc);
}
return rc;
}
static int fdt_driver_init_scan(const void *fdt,