Re: [PATCH 2/2] clk: iproc: fix bit manipulation arithmetic

[Ray Jui]

+ Michael's new email

On 6/29/2015 2:30 PM, Ray Jui wrote:
> A 32-bit variable should be type casted to 64-bit before arithmetic
> operation and assigning it to a 64-bit variable
> 
> Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> Signed-off-by: Ray Jui <rjui@xxxxxxxxxxxx>
> ---
>  drivers/clk/bcm/clk-iproc-pll.c |    5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/bcm/clk-iproc-pll.c b/drivers/clk/bcm/clk-iproc-pll.c
> index a8d971b..2dda4e8 100644
> --- a/drivers/clk/bcm/clk-iproc-pll.c
> +++ b/drivers/clk/bcm/clk-iproc-pll.c
> @@ -366,7 +366,7 @@ static unsigned long iproc_pll_recalc_rate(struct clk_hw *hw,
>  	val = readl(pll->pll_base + ctrl->ndiv_int.offset);
>  	ndiv_int = (val >> ctrl->ndiv_int.shift) &
>  		bit_mask(ctrl->ndiv_int.width);
> -	ndiv = ndiv_int << ctrl->ndiv_int.shift;
> +	ndiv = (u64)ndiv_int << ctrl->ndiv_int.shift;
>  
>  	if (ctrl->flags & IPROC_CLK_PLL_HAS_NDIV_FRAC) {
>  		val = readl(pll->pll_base + ctrl->ndiv_frac.offset);
> @@ -374,7 +374,8 @@ static unsigned long iproc_pll_recalc_rate(struct clk_hw *hw,
>  			bit_mask(ctrl->ndiv_frac.width);
>  
>  		if (ndiv_frac != 0)
> -			ndiv = (ndiv_int << ctrl->ndiv_int.shift) | ndiv_frac;
> +			ndiv = ((u64)ndiv_int << ctrl->ndiv_int.shift) |
> +				ndiv_frac;
>  	}
>  
>  	val = readl(pll->pll_base + ctrl->pdiv.offset);
> 
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