[RESEND PATCH] clk: socfpga: arria10: Optimize local variables in clk_pll_recalc_rate()

Thorsten Blum posted 1 patch 1 year, 3 months ago
drivers/clk/socfpga/clk-pll-a10.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
[RESEND PATCH] clk: socfpga: arria10: Optimize local variables in clk_pll_recalc_rate()
Posted by Thorsten Blum 1 year, 3 months ago
Since readl() returns a u32, the local variable reg can also have the
data type u32. Furthermore, divf and divq are derived from reg and can
also be a u32.

Since do_div() casts the divisor to u32 anyway, changing the data type
of divq to u32 also removes the following Coccinelle/coccicheck warning
reported by do_div.cocci:

  WARNING: do_div() does a 64-by-32 division, please consider using div64_ul instead

Compile-tested only.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
---
 drivers/clk/socfpga/clk-pll-a10.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/socfpga/clk-pll-a10.c b/drivers/clk/socfpga/clk-pll-a10.c
index b028f25c658a..62eed964c3d0 100644
--- a/drivers/clk/socfpga/clk-pll-a10.c
+++ b/drivers/clk/socfpga/clk-pll-a10.c
@@ -35,7 +35,7 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
 					 unsigned long parent_rate)
 {
 	struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
-	unsigned long divf, divq, reg;
+	u32 divf, divq, reg;
 	unsigned long long vco_freq;
 
 	/* read VCO1 reg for numerator and denominator */
-- 
2.47.0
Re: [RESEND PATCH] clk: socfpga: arria10: Optimize local variables in clk_pll_recalc_rate()
Posted by Dinh Nguyen 1 year, 3 months ago

On 10/26/24 10:53, Thorsten Blum wrote:
> Since readl() returns a u32, the local variable reg can also have the
> data type u32. Furthermore, divf and divq are derived from reg and can
> also be a u32.
> 
> Since do_div() casts the divisor to u32 anyway, changing the data type
> of divq to u32 also removes the following Coccinelle/coccicheck warning
> reported by do_div.cocci:
> 
>    WARNING: do_div() does a 64-by-32 division, please consider using div64_ul instead
> 
> Compile-tested only.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
>   drivers/clk/socfpga/clk-pll-a10.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 

Applied, thanks!

Dinh