linux-kernel - Re: [PATCH v2] clk:sophgo: Remove uninitialized variable for CV1800 PLL

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Message-ID: <shbsc7lxtn3fbiq4vixdjprbpxdsgwxgsd2bfziqlsunwvqj3z@tecit4ibpblk>
Date: Fri, 15 Nov 2024 07:29:38 +0800
From: Inochi Amaoto <inochiama@...il.com>
To: Ragavendra <ragavendra.bn@...il.com>, unicorn_wang@...look.com, 
	mturquette@...libre.com, sboyd@...nel.org, inochiama@...look.com
Cc: linux-clk@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] clk:sophgo: Remove uninitialized variable for CV1800
 PLL

On Thu, Nov 14, 2024 at 01:01:15PM -0800, Ragavendra wrote:
> Updating the detected value to 0 in the ipll_find_rate and removing it
> from the method parameters as it does not depend on external input.
> Updating the calls to ipll_find_rate as well and removing the u32 val
> variable from ipll_determine_rate.
> 
> Fixes: 80fd61ec4612 ("clk: sophgo: Add clock support for CV1800 SoC")
> Signed-off-by: Ragavendra Nagraj <ragavendra.bn@...il.com>
> ---
> V1 -> V2: Updated commit log, title and addressed review comments
> ---
>  drivers/clk/sophgo/clk-cv18xx-pll.c | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/clk/sophgo/clk-cv18xx-pll.c b/drivers/clk/sophgo/clk-cv18xx-pll.c
> index 29e24098bf5f..350195d4ac46 100644
> --- a/drivers/clk/sophgo/clk-cv18xx-pll.c
> +++ b/drivers/clk/sophgo/clk-cv18xx-pll.c
> @@ -45,14 +45,13 @@ static unsigned long ipll_recalc_rate(struct clk_hw *hw,
>  }
>  
>  static int ipll_find_rate(const struct cv1800_clk_pll_limit *limit,
> -			  unsigned long prate, unsigned long *rate,
> -			  u32 *value)
> +			  unsigned long prate, unsigned long *rate)
>  {
>  	unsigned long best_rate = 0;
>  	unsigned long trate = *rate;
>  	unsigned long pre_div_sel = 0, div_sel = 0, post_div_sel = 0;
>  	unsigned long pre, div, post;
> -	u32 detected = *value;
> +	u32 detected = 0;
>  	unsigned long tmp;
>  
>  	for_each_pll_limit_range(pre, &limit->pre_div) {
> @@ -77,7 +76,6 @@ static int ipll_find_rate(const struct cv1800_clk_pll_limit *limit,
>  		detected = PLL_SET_PRE_DIV_SEL(detected, pre_div_sel);
>  		detected = PLL_SET_POST_DIV_SEL(detected, post_div_sel);
>  		detected = PLL_SET_DIV_SEL(detected, div_sel);
> -		*value = detected;
>  		*rate = best_rate;
>  		return 0;
>  	}
> @@ -87,11 +85,10 @@ static int ipll_find_rate(const struct cv1800_clk_pll_limit *limit,
>  
>  static int ipll_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
>  {
> -	u32 val;
>  	struct cv1800_clk_pll *pll = hw_to_cv1800_clk_pll(hw);
>  
>  	return ipll_find_rate(pll->pll_limit, req->best_parent_rate,
> -			      &req->rate, &val);
> +			      &req->rate);
>  }
>  
>  static void pll_get_mode_ctrl(unsigned long div_sel,
> @@ -134,7 +131,7 @@ static int ipll_set_rate(struct clk_hw *hw, unsigned long rate,
>  	unsigned long flags;
>  	struct cv1800_clk_pll *pll = hw_to_cv1800_clk_pll(hw);
>  
> -	ipll_find_rate(pll->pll_limit, parent_rate, &rate, &detected);
> +	ipll_find_rate(pll->pll_limit, parent_rate, &rate);

If you remove this, how can the function get the right configuration?
And why you want to remove this? I suspend you did not take my advice
and change nothing. You must check the code logic and do a meaningful
change.

Regards,
Inochi

>  	pll_get_mode_ctrl(PLL_GET_DIV_SEL(detected),
>  			  ipll_check_mode_ctrl_restrict,
>  			  pll->pll_limit, &detected);
> 
> base-commit: 2e1b3cc9d7f790145a80cb705b168f05dab65df2
> -- 
> 2.46.1
>