fsl-layerscape: fix warning if no hwconfig is defined

While getting the 'subarg' of 'hwconfig' env variable in
config_core_prefetch(), if no hwconfig variable is defined,
below warning is received:
WARNING: Calling __hwconfig without a buffer and
	before environment is ready

Fix this by checking 'hwconfig' env variable.
If not found return without further processing.

Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>
Tested-by: Michael Walle <michael@walle.cc>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
index 1f4c0b29a37..83a33193211 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
+++ b/arch/arm/cpu/armv8/fsl-layerscape/cpu.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0+
 /*
- * Copyright 2017 NXP
+ * Copyright 2017-2019 NXP
  * Copyright 2014-2015 Freescale Semiconductor, Inc.
  */
 
@@ -1072,6 +1072,8 @@ static void config_core_prefetch(void)
 
 	if (env_get_f("hwconfig", buffer, sizeof(buffer)) > 0)
 		buf = buffer;
+	else
+		return;
 
 	prefetch_arg = hwconfig_subarg_f("core_prefetch", "disable",
 					 &arglen, buf);