LinuxLists.cc - [PATCH v2] clk: sunxi-ng: Avoid computing the rate twice

2022-12-31 17:57:10

Subject: [PATCH v2] clk: sunxi-ng: Avoid computing the rate twice

The ccu_*_find_best() functions already compute a best_rate at the same
time as the other factors. Return this value so the caller does not need
to duplicate the computation.

Signed-off-by: Samuel Holland <[email protected]>
---

Changes in v2:
- Apply the same change also to nk, nkm, nkmp, and nm
- Update the commit message

drivers/clk/sunxi-ng/ccu_mp.c | 11 ++++++-----
drivers/clk/sunxi-ng/ccu_nk.c | 9 +++++----
drivers/clk/sunxi-ng/ccu_nkm.c | 10 +++++-----
drivers/clk/sunxi-ng/ccu_nkmp.c | 10 +++++-----
drivers/clk/sunxi-ng/ccu_nm.c | 9 +++++----
5 files changed, 26 insertions(+), 23 deletions(-)

diff --git a/drivers/clk/sunxi-ng/ccu_mp.c b/drivers/clk/sunxi-ng/ccu_mp.c
index 57cf2d615148..cc94a694cb67 100644
--- a/drivers/clk/sunxi-ng/ccu_mp.c
+++ b/drivers/clk/sunxi-ng/ccu_mp.c
@@ -10,9 +10,9 @@
#include "ccu_gate.h"
#include "ccu_mp.h"

-static void ccu_mp_find_best(unsigned long parent, unsigned long rate,
- unsigned int max_m, unsigned int max_p,
- unsigned int *m, unsigned int *p)
+static unsigned long ccu_mp_find_best(unsigned long parent, unsigned long rate,
+ unsigned int max_m, unsigned int max_p,
+ unsigned int *m, unsigned int *p)
{
unsigned long best_rate = 0;
unsigned int best_m = 0, best_p = 0;
@@ -35,6 +35,8 @@ static void ccu_mp_find_best(unsigned long parent, unsigned long rate,

*m = best_m;
*p = best_p;
+
+ return best_rate;
}

static unsigned long ccu_mp_find_best_with_parent_adj(struct clk_hw *hw,
@@ -109,8 +111,7 @@ static unsigned long ccu_mp_round_rate(struct ccu_mux_internal *mux,
max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1);

if (!clk_hw_can_set_rate_parent(&cmp->common.hw)) {
- ccu_mp_find_best(*parent_rate, rate, max_m, max_p, &m, &p);
- rate = *parent_rate / p / m;
+ rate = ccu_mp_find_best(*parent_rate, rate, max_m, max_p, &m, &p);
} else {
rate = ccu_mp_find_best_with_parent_adj(hw, parent_rate, rate,
max_m, max_p);
diff --git a/drivers/clk/sunxi-ng/ccu_nk.c b/drivers/clk/sunxi-ng/ccu_nk.c
index c4fb82af97e8..8aa35d5804f3 100644
--- a/drivers/clk/sunxi-ng/ccu_nk.c
+++ b/drivers/clk/sunxi-ng/ccu_nk.c
@@ -15,8 +15,8 @@ struct _ccu_nk {
unsigned long k, min_k, max_k;
};

-static void ccu_nk_find_best(unsigned long parent, unsigned long rate,
- struct _ccu_nk *nk)
+static unsigned long ccu_nk_find_best(unsigned long parent, unsigned long rate,
+ struct _ccu_nk *nk)
{
unsigned long best_rate = 0;
unsigned int best_k = 0, best_n = 0;
@@ -39,6 +39,8 @@ static void ccu_nk_find_best(unsigned long parent, unsigned long rate,

nk->k = best_k;
nk->n = best_n;
+
+ return best_rate;
}

static void ccu_nk_disable(struct clk_hw *hw)
@@ -104,8 +106,7 @@ static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long rate,
_nk.min_k = nk->k.min ?: 1;
_nk.max_k = nk->k.max ?: 1 << nk->k.width;

- ccu_nk_find_best(*parent_rate, rate, &_nk);
- rate = *parent_rate * _nk.n * _nk.k;
+ rate = ccu_nk_find_best(*parent_rate, rate, &_nk);

if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate = rate / nk->fixed_post_div;
diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
index 67da2c189b53..a0978a50edae 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.c
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
@@ -16,8 +16,8 @@ struct _ccu_nkm {
unsigned long m, min_m, max_m;
};

-static void ccu_nkm_find_best(unsigned long parent, unsigned long rate,
- struct _ccu_nkm *nkm)
+static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
+ struct _ccu_nkm *nkm)
{
unsigned long best_rate = 0;
unsigned long best_n = 0, best_k = 0, best_m = 0;
@@ -45,6 +45,8 @@ static void ccu_nkm_find_best(unsigned long parent, unsigned long rate,
nkm->n = best_n;
nkm->k = best_k;
nkm->m = best_m;
+
+ return best_rate;
}

static void ccu_nkm_disable(struct clk_hw *hw)
@@ -122,9 +124,7 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate *= nkm->fixed_post_div;

- ccu_nkm_find_best(*parent_rate, rate, &_nkm);
-
- rate = *parent_rate * _nkm.n * _nkm.k / _nkm.m;
+ rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm);

if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nkm->fixed_post_div;
diff --git a/drivers/clk/sunxi-ng/ccu_nkmp.c b/drivers/clk/sunxi-ng/ccu_nkmp.c
index 39413cb0985c..99359a06892d 100644
--- a/drivers/clk/sunxi-ng/ccu_nkmp.c
+++ b/drivers/clk/sunxi-ng/ccu_nkmp.c
@@ -29,8 +29,8 @@ static unsigned long ccu_nkmp_calc_rate(unsigned long parent,
return rate;
}

-static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
- struct _ccu_nkmp *nkmp)
+static unsigned long ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
+ struct _ccu_nkmp *nkmp)
{
unsigned long best_rate = 0;
unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0;
@@ -65,6 +65,8 @@ static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
nkmp->k = best_k;
nkmp->m = best_m;
nkmp->p = best_p;
+
+ return best_rate;
}

static void ccu_nkmp_disable(struct clk_hw *hw)
@@ -150,10 +152,8 @@ static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate,
_nkmp.min_p = 1;
_nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1);

- ccu_nkmp_find_best(*parent_rate, rate, &_nkmp);
+ rate = ccu_nkmp_find_best(*parent_rate, rate, &_nkmp);

- rate = ccu_nkmp_calc_rate(*parent_rate, _nkmp.n, _nkmp.k,
- _nkmp.m, _nkmp.p);
if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate = rate / nkmp->fixed_post_div;

diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c
index 9ca9257f4426..c1fd11542c45 100644
--- a/drivers/clk/sunxi-ng/ccu_nm.c
+++ b/drivers/clk/sunxi-ng/ccu_nm.c
@@ -27,8 +27,8 @@ static unsigned long ccu_nm_calc_rate(unsigned long parent,
return rate;
}

-static void ccu_nm_find_best(unsigned long parent, unsigned long rate,
- struct _ccu_nm *nm)
+static unsigned long ccu_nm_find_best(unsigned long parent, unsigned long rate,
+ struct _ccu_nm *nm)
{
unsigned long best_rate = 0;
unsigned long best_n = 0, best_m = 0;
@@ -52,6 +52,8 @@ static void ccu_nm_find_best(unsigned long parent, unsigned long rate,

nm->n = best_n;
nm->m = best_m;
+
+ return best_rate;
}

static void ccu_nm_disable(struct clk_hw *hw)
@@ -157,8 +159,7 @@ static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
_nm.min_m = 1;
_nm.max_m = nm->m.max ?: 1 << nm->m.width;

- ccu_nm_find_best(*parent_rate, rate, &_nm);
- rate = ccu_nm_calc_rate(*parent_rate, _nm.n, _nm.m);
+ rate = ccu_nm_find_best(*parent_rate, rate, &_nm);

if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nm->fixed_post_div;
--
2.37.4

2023-01-03 11:31:23

by Andre Przywara

[permalink] [raw]

Subject: Re: [PATCH v2] clk: sunxi-ng: Avoid computing the rate twice

On Sat, 31 Dec 2022 11:30:55 -0600
Samuel Holland <[email protected]> wrote:

Hi,

> The ccu_*_find_best() functions already compute a best_rate at the same
> time as the other factors. Return this value so the caller does not need
> to duplicate the computation.
>
> Signed-off-by: Samuel Holland <[email protected]>

Checked for all five files that the internal calculation in find_best()
matches the one it replaces here:

Reviewed-by: Andre Przywara <[email protected]>

Cheers,
Andre

> ---
>
> Changes in v2:
> - Apply the same change also to nk, nkm, nkmp, and nm
> - Update the commit message
>
> drivers/clk/sunxi-ng/ccu_mp.c | 11 ++++++-----
> drivers/clk/sunxi-ng/ccu_nk.c | 9 +++++----
> drivers/clk/sunxi-ng/ccu_nkm.c | 10 +++++-----
> drivers/clk/sunxi-ng/ccu_nkmp.c | 10 +++++-----
> drivers/clk/sunxi-ng/ccu_nm.c | 9 +++++----
> 5 files changed, 26 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/clk/sunxi-ng/ccu_mp.c b/drivers/clk/sunxi-ng/ccu_mp.c
> index 57cf2d615148..cc94a694cb67 100644
> --- a/drivers/clk/sunxi-ng/ccu_mp.c
> +++ b/drivers/clk/sunxi-ng/ccu_mp.c
> @@ -10,9 +10,9 @@
> #include "ccu_gate.h"
> #include "ccu_mp.h"
>
> -static void ccu_mp_find_best(unsigned long parent, unsigned long rate,
> - unsigned int max_m, unsigned int max_p,
> - unsigned int *m, unsigned int *p)
> +static unsigned long ccu_mp_find_best(unsigned long parent, unsigned long rate,
> + unsigned int max_m, unsigned int max_p,
> + unsigned int *m, unsigned int *p)
> {
> unsigned long best_rate = 0;
> unsigned int best_m = 0, best_p = 0;
> @@ -35,6 +35,8 @@ static void ccu_mp_find_best(unsigned long parent, unsigned long rate,
>
> *m = best_m;
> *p = best_p;
> +
> + return best_rate;
> }
>
> static unsigned long ccu_mp_find_best_with_parent_adj(struct clk_hw *hw,
> @@ -109,8 +111,7 @@ static unsigned long ccu_mp_round_rate(struct ccu_mux_internal *mux,
> max_p = cmp->p.max ?: 1 << ((1 << cmp->p.width) - 1);
>
> if (!clk_hw_can_set_rate_parent(&cmp->common.hw)) {
> - ccu_mp_find_best(*parent_rate, rate, max_m, max_p, &m, &p);
> - rate = *parent_rate / p / m;
> + rate = ccu_mp_find_best(*parent_rate, rate, max_m, max_p, &m, &p);
> } else {
> rate = ccu_mp_find_best_with_parent_adj(hw, parent_rate, rate,
> max_m, max_p);
> diff --git a/drivers/clk/sunxi-ng/ccu_nk.c b/drivers/clk/sunxi-ng/ccu_nk.c
> index c4fb82af97e8..8aa35d5804f3 100644
> --- a/drivers/clk/sunxi-ng/ccu_nk.c
> +++ b/drivers/clk/sunxi-ng/ccu_nk.c
> @@ -15,8 +15,8 @@ struct _ccu_nk {
> unsigned long k, min_k, max_k;
> };
>
> -static void ccu_nk_find_best(unsigned long parent, unsigned long rate,
> - struct _ccu_nk *nk)
> +static unsigned long ccu_nk_find_best(unsigned long parent, unsigned long rate,
> + struct _ccu_nk *nk)
> {
> unsigned long best_rate = 0;
> unsigned int best_k = 0, best_n = 0;
> @@ -39,6 +39,8 @@ static void ccu_nk_find_best(unsigned long parent, unsigned long rate,
>
> nk->k = best_k;
> nk->n = best_n;
> +
> + return best_rate;
> }
>
> static void ccu_nk_disable(struct clk_hw *hw)
> @@ -104,8 +106,7 @@ static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long rate,
> _nk.min_k = nk->k.min ?: 1;
> _nk.max_k = nk->k.max ?: 1 << nk->k.width;
>
> - ccu_nk_find_best(*parent_rate, rate, &_nk);
> - rate = *parent_rate * _nk.n * _nk.k;
> + rate = ccu_nk_find_best(*parent_rate, rate, &_nk);
>
> if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
> rate = rate / nk->fixed_post_div;
> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
> index 67da2c189b53..a0978a50edae 100644
> --- a/drivers/clk/sunxi-ng/ccu_nkm.c
> +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
> @@ -16,8 +16,8 @@ struct _ccu_nkm {
> unsigned long m, min_m, max_m;
> };
>
> -static void ccu_nkm_find_best(unsigned long parent, unsigned long rate,
> - struct _ccu_nkm *nkm)
> +static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
> + struct _ccu_nkm *nkm)
> {
> unsigned long best_rate = 0;
> unsigned long best_n = 0, best_k = 0, best_m = 0;
> @@ -45,6 +45,8 @@ static void ccu_nkm_find_best(unsigned long parent, unsigned long rate,
> nkm->n = best_n;
> nkm->k = best_k;
> nkm->m = best_m;
> +
> + return best_rate;
> }
>
> static void ccu_nkm_disable(struct clk_hw *hw)
> @@ -122,9 +124,7 @@ static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
> if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
> rate *= nkm->fixed_post_div;
>
> - ccu_nkm_find_best(*parent_rate, rate, &_nkm);
> -
> - rate = *parent_rate * _nkm.n * _nkm.k / _nkm.m;
> + rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm);
>
> if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
> rate /= nkm->fixed_post_div;
> diff --git a/drivers/clk/sunxi-ng/ccu_nkmp.c b/drivers/clk/sunxi-ng/ccu_nkmp.c
> index 39413cb0985c..99359a06892d 100644
> --- a/drivers/clk/sunxi-ng/ccu_nkmp.c
> +++ b/drivers/clk/sunxi-ng/ccu_nkmp.c
> @@ -29,8 +29,8 @@ static unsigned long ccu_nkmp_calc_rate(unsigned long parent,
> return rate;
> }
>
> -static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
> - struct _ccu_nkmp *nkmp)
> +static unsigned long ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
> + struct _ccu_nkmp *nkmp)
> {
> unsigned long best_rate = 0;
> unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0;
> @@ -65,6 +65,8 @@ static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
> nkmp->k = best_k;
> nkmp->m = best_m;
> nkmp->p = best_p;
> +
> + return best_rate;
> }
>
> static void ccu_nkmp_disable(struct clk_hw *hw)
> @@ -150,10 +152,8 @@ static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate,
> _nkmp.min_p = 1;
> _nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1);
>
> - ccu_nkmp_find_best(*parent_rate, rate, &_nkmp);
> + rate = ccu_nkmp_find_best(*parent_rate, rate, &_nkmp);
>
> - rate = ccu_nkmp_calc_rate(*parent_rate, _nkmp.n, _nkmp.k,
> - _nkmp.m, _nkmp.p);
> if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
> rate = rate / nkmp->fixed_post_div;
>
> diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c
> index 9ca9257f4426..c1fd11542c45 100644
> --- a/drivers/clk/sunxi-ng/ccu_nm.c
> +++ b/drivers/clk/sunxi-ng/ccu_nm.c
> @@ -27,8 +27,8 @@ static unsigned long ccu_nm_calc_rate(unsigned long parent,
> return rate;
> }
>
> -static void ccu_nm_find_best(unsigned long parent, unsigned long rate,
> - struct _ccu_nm *nm)
> +static unsigned long ccu_nm_find_best(unsigned long parent, unsigned long rate,
> + struct _ccu_nm *nm)
> {
> unsigned long best_rate = 0;
> unsigned long best_n = 0, best_m = 0;
> @@ -52,6 +52,8 @@ static void ccu_nm_find_best(unsigned long parent, unsigned long rate,
>
> nm->n = best_n;
> nm->m = best_m;
> +
> + return best_rate;
> }
>
> static void ccu_nm_disable(struct clk_hw *hw)
> @@ -157,8 +159,7 @@ static long ccu_nm_round_rate(struct clk_hw *hw, unsigned long rate,
> _nm.min_m = 1;
> _nm.max_m = nm->m.max ?: 1 << nm->m.width;
>
> - ccu_nm_find_best(*parent_rate, rate, &_nm);
> - rate = ccu_nm_calc_rate(*parent_rate, _nm.n, _nm.m);
> + rate = ccu_nm_find_best(*parent_rate, rate, &_nm);
>
> if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV)
> rate /= nm->fixed_post_div;

2023-01-05 17:03:47

by Jernej Škrabec

[permalink] [raw]

Subject: Re: [PATCH v2] clk: sunxi-ng: Avoid computing the rate twice

Dne sobota, 31. december 2022 ob 18:30:55 CET je Samuel Holland napisal(a):
> The ccu_*_find_best() functions already compute a best_rate at the same
> time as the other factors. Return this value so the caller does not need
> to duplicate the computation.
>
> Signed-off-by: Samuel Holland <[email protected]>

Reviewed-by: Jernej Skrabec <[email protected]>

Best regards,
Jernej

2023-01-08 21:49:25

by Jernej Škrabec

[permalink] [raw]