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From 89e28da82836530f1ac7a3a32fecc31f22d79b3e Mon Sep 17 00:00:00 2001
From: Nathan Chancellor <natechancellor@gmail.com>
Date: Thu, 7 Mar 2019 15:56:51 -0700
Subject: [PATCH] soc: mediatek: pwrap: Zero initialize rdata in pwrap_init_cipher
Git-commit: 89e28da82836530f1ac7a3a32fecc31f22d79b3e
Patch-mainline: v5.2-rc1
References: bsc#1051510

When building with -Wsometimes-uninitialized, Clang warns:

drivers/soc/mediatek/mtk-pmic-wrap.c:1358:6: error: variable 'rdata' is
used uninitialized whenever '||' condition is true
[-Werror,-Wsometimes-uninitialized]

If pwrap_write returns non-zero, pwrap_read will not be called to
initialize rdata, meaning that we will use some random uninitialized
stack value in our print statement. Zero initialize rdata in case this
happens.

Link: https://github.com/ClangBuiltLinux/linux/issues/401
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/soc/mediatek/mtk-pmic-wrap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soc/mediatek/mtk-pmic-wrap.c b/drivers/soc/mediatek/mtk-pmic-wrap.c
index 73f0be0567bd..c4449a163991 100644
--- a/drivers/soc/mediatek/mtk-pmic-wrap.c
+++ b/drivers/soc/mediatek/mtk-pmic-wrap.c
@@ -1371,7 +1371,7 @@ static bool pwrap_is_pmic_cipher_ready(struct pmic_wrapper *wrp)
 static int pwrap_init_cipher(struct pmic_wrapper *wrp)
 {
 	int ret;
-	u32 rdata;
+	u32 rdata = 0;
 
 	pwrap_writel(wrp, 0x1, PWRAP_CIPHER_SWRST);
 	pwrap_writel(wrp, 0x0, PWRAP_CIPHER_SWRST);
-- 
2.16.4