MIPS: BCM63XX: Make nvram checksum failure non fatal

Some vendors modify the nvram layout moving the checksum to a different
place or dropping entirely, so reduce the checksum failure to a warning.
Reported-by: Álvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: Jonas Gorski <jogo@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: John Crispin <blogic@openwrt.org>
Cc: Maxime Bizon <mbizon@freebox.fr>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/bcm63xx/boards/board_bcm963xx.c

@@ -745,10 +745,7 @@ void __init board_prom_init(void)
 		strcpy(cfe_version, "unknown");
 	printk(KERN_INFO PFX "CFE version: %s\n", cfe_version);
 
-	if (bcm63xx_nvram_init(boot_addr + BCM963XX_NVRAM_OFFSET)) {
-		printk(KERN_ERR PFX "invalid nvram checksum\n");
-		return;
-	}
+	bcm63xx_nvram_init(boot_addr + BCM963XX_NVRAM_OFFSET);
 
 	board_name = bcm63xx_nvram_get_name();
 	/* find board by name */

arch/mips/bcm63xx/nvram.c

@@ -38,7 +38,7 @@ struct bcm963xx_nvram {
 static struct bcm963xx_nvram nvram;
 static int mac_addr_used;
 
-int __init bcm63xx_nvram_init(void *addr)
+void __init bcm63xx_nvram_init(void *addr)
 {
 	unsigned int check_len;
 	u32 crc, expected_crc;
@@ -60,9 +60,8 @@ int __init bcm63xx_nvram_init(void *addr)
 	crc = crc32_le(~0, (u8 *)&nvram, check_len);
 
 	if (crc != expected_crc)
-		return -EINVAL;
-
-	return 0;
+		pr_warn("nvram checksum failed, contents may be invalid (expected %08x, got %08x)\n",
+			expected_crc, crc);
 }
 
 u8 *bcm63xx_nvram_get_name(void)

arch/mips/include/asm/mach-bcm63xx/bcm63xx_nvram.h

@@ -9,10 +9,8 @@
  *
  * Initialized the local nvram copy from the target address and checks
  * its checksum.
- *
- * Returns 0 on success.
  */
-int __init bcm63xx_nvram_init(void *nvram);
+void bcm63xx_nvram_init(void *nvram);
 
 /**
  * bcm63xx_nvram_get_name() - returns the board name according to nvram