[U-Boot] [PATCH v2] fdt_support: Fixup 'ethernet' aliases not ending in digits

[Tuomas Tynkkynen]

The Raspberry Pi device tree files since Linux v4.9 have a "ethernet"
alias pointing to the on-board Ethernet device node. However,
U-Boot's fdt_fixup_ethernet() only looks at ethernet aliases ending
in digits.

As the spec doesn't mandate that aliases must end in numbers and there
have been much older uses of an "ethernet" aliases in the wild
(according to Tom Rini), change the code to accept "ethernet" as well.

Without this Linux isn't told of the MAC address provided by the
RPI firmware and the ethernet interface is always assigned a random MAC
address.

Signed-off-by: Tuomas Tynkkynen <tuomas at tuxera.com>
---
v2: Change code & commit messages to imply that plain 'ethernet' usage
    is not a bug in the DT, kill the 'len' variable.
 common/fdt_support.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/common/fdt_support.c b/common/fdt_support.c
index 55d4d6f6d4..c6a76b7ad2 100644
--- a/common/fdt_support.c
+++ b/common/fdt_support.c
@@ -482,7 +482,6 @@ void fdt_fixup_ethernet(void *fdt)
 	/* Cycle through all aliases */
 	for (prop = 0; ; prop++) {
 		const char *name;
-		int len = strlen("ethernet");
 
 		/* FDT might have been edited, recompute the offset */
 		offset = fdt_first_property_offset(fdt,
@@ -495,8 +494,13 @@ void fdt_fixup_ethernet(void *fdt)
 			break;
 
 		path = fdt_getprop_by_offset(fdt, offset, &name, NULL);
-		if (!strncmp(name, "ethernet", len)) {
-			i = trailing_strtol(name);
+		if (!strncmp(name, "ethernet", 8)) {
+			/* Treat plain "ethernet" same as "ethernet0". */
+			if (!strcmp(name, "ethernet"))
+				i = 0;
+			else
+				i = trailing_strtol(name);
+
 			if (i != -1) {
 				if (i == 0)
 					strcpy(mac, "ethaddr");
-- 
2.11.1