From b56f67a6c748bb009f313f91651c8020d2338d63 Mon Sep 17 00:00:00 2001
From: Jiaxun Yang <jiaxun.yang@flygoat.com>
Date: Mon, 3 Jun 2024 15:45:53 +0800
Subject: [PATCH] LoongArch: Fix built-in DTB detection
fdt_check_header(__dtb_start) will always success because kernel
provides a dummy dtb, and by coincidence __dtb_start clashed with
entry of this dummy dtb. The consequence is fdt passed from firmware
will never be taken.
Fix by trying to utilise __dtb_start only when CONFIG_BUILTIN_DTB is
enabled.
Cc: stable@vger.kernel.org
Fixes: 7b937cc243e5 ("of: Create of_root if no dtb provided by firmware")
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
arch/loongarch/kernel/setup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
index 89ad756aeeed2..3d048f1be1438 100644
--- a/arch/loongarch/kernel/setup.c
+++ b/arch/loongarch/kernel/setup.c
@@ -282,7 +282,7 @@ static void __init fdt_setup(void)
return;
/* Prefer to use built-in dtb, checking its legality first. */
- if (!fdt_check_header(__dtb_start))
+ if (IS_ENABLED(CONFIG_BUILTIN_DTB) && !fdt_check_header(__dtb_start))
fdt_pointer = __dtb_start;
else
fdt_pointer = efi_fdt_pointer(); /* Fallback to firmware dtb */
--
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