[PATCH 4.9 27/29] fdt: Update CRC check for rng-seed

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Hsin-Yi Wang <hsinyi@chromium.org>

commit dd753d961c4844a39f947be115b3d81e10376ee5 upstream.

Commit 428826f5358c ("fdt: add support for rng-seed") moves of_fdt_crc32
from early_init_dt_verify() to early_init_dt_scan() since
early_init_dt_scan_chosen() may modify fdt to erase rng-seed.

However, arm and some other arch won't call early_init_dt_scan(), they
call early_init_dt_verify() then early_init_dt_scan_nodes().

Restore of_fdt_crc32 to early_init_dt_verify() then update it in
early_init_dt_scan_chosen() if fdt if updated.

Fixes: 428826f5358c ("fdt: add support for rng-seed")
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/of/fdt.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -1110,6 +1110,10 @@ int __init early_init_dt_scan_chosen(uns
 
 		/* try to clear seed so it won't be found. */
 		fdt_nop_property(initial_boot_params, node, "rng-seed");
+
+		/* update CRC check value */
+		of_fdt_crc32 = crc32_be(~0, initial_boot_params,
+				fdt_totalsize(initial_boot_params));
 	}
 
 	/* break now */
@@ -1213,6 +1217,8 @@ bool __init early_init_dt_verify(void *p
 
 	/* Setup flat device-tree pointer */
 	initial_boot_params = params;
+	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
+				fdt_totalsize(initial_boot_params));
 	return true;
 }
 
@@ -1238,8 +1244,6 @@ bool __init early_init_dt_scan(void *par
 		return false;
 
 	early_init_dt_scan_nodes();
-	of_fdt_crc32 = crc32_be(~0, initial_boot_params,
-				fdt_totalsize(initial_boot_params));
 	return true;
 }