[PATCH 11/11] mfd: sm501: Avoid implicit sign extension

Lee Jones lee.jones at linaro.org
Thu Aug 28 06:14:17 PDT 2014


Suspicious implicit sign extension where 'reg' (unsigned char) is
promoted in reg << clksrc to int, then sign-extended to unsigned
long. If reg << clksrc is greater than 0x7FFFFFFF, the upper bits
of the result will all be 1.

Signed-off-by: Lee Jones <lee.jones at linaro.org>
---
 drivers/mfd/sm501.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mfd/sm501.c b/drivers/mfd/sm501.c
index 81e6d09..1f9233b 100644
--- a/drivers/mfd/sm501.c
+++ b/drivers/mfd/sm501.c
@@ -514,9 +514,9 @@ unsigned long sm501_set_clock(struct device *dev,
 	unsigned long mode = smc501_readl(sm->regs + SM501_POWER_MODE_CONTROL);
 	unsigned long gate = smc501_readl(sm->regs + SM501_CURRENT_GATE);
 	unsigned long clock = smc501_readl(sm->regs + SM501_CURRENT_CLOCK);
-	unsigned char reg;
 	unsigned int pll_reg = 0;
 	unsigned long sm501_freq; /* the actual frequency achieved */
+	u64 reg;
 
 	struct sm501_clock to;
 
-- 
1.9.1




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