| Message ID | 20240801103616.20430-1-thorsten.blum@toblux.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | [v2] clk: hisilicon: Remove unnecessary local variable | expand |
Hello, On Thu, Aug 01, 2024 at 12:36:16PM +0200, Thorsten Blum wrote: > The local u64 variable refdiv_val has the same value as the local u32 > variable val and can be removed. Remove it and use val directly as the > divisor to also remove the following Coccinelle/coccicheck warning > reported by do_div.cocci: > > WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead > > Use the preferred div_u64() function instead of the do_div() macro. > > Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> > --- > Changes in v2: > - Use div_u64() instead of do_div() as suggested by Stephen Boyd > - Link to v1: https://lore.kernel.org/linux-kernel/20240710201844.710365-2-thorsten.blum@toblux.com/ > --- > drivers/clk/hisilicon/clk-hi3559a.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/clk/hisilicon/clk-hi3559a.c b/drivers/clk/hisilicon/clk-hi3559a.c > index c79a94f6d9d2..8646e9d352ed 100644 > --- a/drivers/clk/hisilicon/clk-hi3559a.c > +++ b/drivers/clk/hisilicon/clk-hi3559a.c > @@ -407,7 +407,7 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw, > unsigned long parent_rate) > { > struct hi3559av100_clk_pll *clk = to_pll_clk(hw); > - u64 frac_val, fbdiv_val, refdiv_val; > + u64 frac_val, fbdiv_val; > u32 postdiv1_val, postdiv2_val; > u32 val; > u64 tmp, rate; > @@ -435,14 +435,13 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw, > val = readl_relaxed(clk->ctrl_reg2); > val = val >> clk->refdiv_shift; > val &= ((1 << clk->refdiv_width) - 1); > - refdiv_val = val; > > /* rate = 24000000 * (fbdiv + frac / (1<<24) ) / refdiv */ > rate = 0; > tmp = 24000000 * fbdiv_val + (24000000 * frac_val) / (1 << 24); > rate += tmp; > - do_div(rate, refdiv_val); > - do_div(rate, postdiv1_val * postdiv2_val); > + rate = div_u64(rate, val); > + rate = div_u64(rate, postdiv1_val * postdiv2_val); Without looking at the bigger context: Can postdiv1_val * postdiv2_val overflow? (If this is a problem, fixing it justifies another patch, so this concern shouldn't stop this patch from being accepted.) Otherwise looks fine, Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com> Best regards Uwe
Quoting Thorsten Blum (2024-08-01 03:36:16) > The local u64 variable refdiv_val has the same value as the local u32 > variable val and can be removed. Remove it and use val directly as the > divisor to also remove the following Coccinelle/coccicheck warning > reported by do_div.cocci: > > WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead > > Use the preferred div_u64() function instead of the do_div() macro. > > Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> > --- Applied to clk-next
diff --git a/drivers/clk/hisilicon/clk-hi3559a.c b/drivers/clk/hisilicon/clk-hi3559a.c index c79a94f6d9d2..8646e9d352ed 100644 --- a/drivers/clk/hisilicon/clk-hi3559a.c +++ b/drivers/clk/hisilicon/clk-hi3559a.c @@ -407,7 +407,7 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct hi3559av100_clk_pll *clk = to_pll_clk(hw); - u64 frac_val, fbdiv_val, refdiv_val; + u64 frac_val, fbdiv_val; u32 postdiv1_val, postdiv2_val; u32 val; u64 tmp, rate; @@ -435,14 +435,13 @@ static unsigned long clk_pll_recalc_rate(struct clk_hw *hw, val = readl_relaxed(clk->ctrl_reg2); val = val >> clk->refdiv_shift; val &= ((1 << clk->refdiv_width) - 1); - refdiv_val = val; /* rate = 24000000 * (fbdiv + frac / (1<<24) ) / refdiv */ rate = 0; tmp = 24000000 * fbdiv_val + (24000000 * frac_val) / (1 << 24); rate += tmp; - do_div(rate, refdiv_val); - do_div(rate, postdiv1_val * postdiv2_val); + rate = div_u64(rate, val); + rate = div_u64(rate, postdiv1_val * postdiv2_val); return rate; }
The local u64 variable refdiv_val has the same value as the local u32 variable val and can be removed. Remove it and use val directly as the divisor to also remove the following Coccinelle/coccicheck warning reported by do_div.cocci: WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead Use the preferred div_u64() function instead of the do_div() macro. Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com> --- Changes in v2: - Use div_u64() instead of do_div() as suggested by Stephen Boyd - Link to v1: https://lore.kernel.org/linux-kernel/20240710201844.710365-2-thorsten.blum@toblux.com/ --- drivers/clk/hisilicon/clk-hi3559a.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)