* [PATCH] clk: sunxi-ng: mp: Avoid computing the rate twice
@ 2022-08-10 1:40 ` Samuel Holland
0 siblings, 0 replies; 8+ messages in thread
From: Samuel Holland @ 2022-08-10 1:40 UTC (permalink / raw)
To: Chen-Yu Tsai, Jernej Skrabec
Cc: Samuel Holland, Michael Turquette, Stephen Boyd,
linux-arm-kernel, linux-clk, linux-kernel, linux-sunxi
ccu_mp_find_best() already computes a best_rate at the same time as the
best m and p factors. Return it so the caller does not need to duplicate
the division.
Signed-off-by: Samuel Holland <samuel@sholland.org>
---
drivers/clk/sunxi-ng/ccu_mp.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 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);
--
2.35.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH] clk: sunxi-ng: mp: Avoid computing the rate twice
@ 2022-08-10 1:40 ` Samuel Holland
0 siblings, 0 replies; 8+ messages in thread
From: Samuel Holland @ 2022-08-10 1:40 UTC (permalink / raw)
To: Chen-Yu Tsai, Jernej Skrabec
Cc: Samuel Holland, Michael Turquette, Stephen Boyd,
linux-arm-kernel, linux-clk, linux-kernel, linux-sunxi
ccu_mp_find_best() already computes a best_rate at the same time as the
best m and p factors. Return it so the caller does not need to duplicate
the division.
Signed-off-by: Samuel Holland <samuel@sholland.org>
---
drivers/clk/sunxi-ng/ccu_mp.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 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);
--
2.35.1
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http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [PATCH] clk: sunxi-ng: mp: Avoid computing the rate twice
2022-08-10 1:40 ` Samuel Holland
@ 2022-08-14 10:02 ` Jernej Škrabec
-1 siblings, 0 replies; 8+ messages in thread
From: Jernej Škrabec @ 2022-08-14 10:02 UTC (permalink / raw)
To: Chen-Yu Tsai, Samuel Holland
Cc: Samuel Holland, Michael Turquette, Stephen Boyd,
linux-arm-kernel, linux-clk, linux-kernel, linux-sunxi
Dne sreda, 10. avgust 2022 ob 03:40:24 CEST je Samuel Holland napisal(a):
> ccu_mp_find_best() already computes a best_rate at the same time as the
> best m and p factors. Return it so the caller does not need to duplicate
> the division.
>
> Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Other ccu_*_find_best() functions would also benefit with similar change.
Best regards,
Jernej
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] clk: sunxi-ng: mp: Avoid computing the rate twice
@ 2022-08-14 10:02 ` Jernej Škrabec
0 siblings, 0 replies; 8+ messages in thread
From: Jernej Škrabec @ 2022-08-14 10:02 UTC (permalink / raw)
To: Chen-Yu Tsai, Samuel Holland
Cc: Samuel Holland, Michael Turquette, Stephen Boyd,
linux-arm-kernel, linux-clk, linux-kernel, linux-sunxi
Dne sreda, 10. avgust 2022 ob 03:40:24 CEST je Samuel Holland napisal(a):
> ccu_mp_find_best() already computes a best_rate at the same time as the
> best m and p factors. Return it so the caller does not need to duplicate
> the division.
>
> Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Other ccu_*_find_best() functions would also benefit with similar change.
Best regards,
Jernej
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] clk: sunxi-ng: mp: Avoid computing the rate twice
2022-08-10 1:40 ` Samuel Holland
@ 2022-08-15 17:26 ` Stephen Boyd
-1 siblings, 0 replies; 8+ messages in thread
From: Stephen Boyd @ 2022-08-15 17:26 UTC (permalink / raw)
To: Chen-Yu Tsai, Jernej Skrabec, Samuel Holland
Cc: Samuel Holland, Michael Turquette, linux-arm-kernel, linux-clk,
linux-kernel, linux-sunxi
Quoting Samuel Holland (2022-08-09 18:40:24)
> ccu_mp_find_best() already computes a best_rate at the same time as the
> best m and p factors. Return it so the caller does not need to duplicate
> the division.
Did the compiler figure this out and thus this patch makes no difference
to the final object code?
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] clk: sunxi-ng: mp: Avoid computing the rate twice
@ 2022-08-15 17:26 ` Stephen Boyd
0 siblings, 0 replies; 8+ messages in thread
From: Stephen Boyd @ 2022-08-15 17:26 UTC (permalink / raw)
To: Chen-Yu Tsai, Jernej Skrabec, Samuel Holland
Cc: Samuel Holland, Michael Turquette, linux-arm-kernel, linux-clk,
linux-kernel, linux-sunxi
Quoting Samuel Holland (2022-08-09 18:40:24)
> ccu_mp_find_best() already computes a best_rate at the same time as the
> best m and p factors. Return it so the caller does not need to duplicate
> the division.
Did the compiler figure this out and thus this patch makes no difference
to the final object code?
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] clk: sunxi-ng: mp: Avoid computing the rate twice
2022-08-15 17:26 ` Stephen Boyd
@ 2022-12-31 17:21 ` Samuel Holland
-1 siblings, 0 replies; 8+ messages in thread
From: Samuel Holland @ 2022-12-31 17:21 UTC (permalink / raw)
To: Stephen Boyd, Chen-Yu Tsai, Jernej Skrabec
Cc: Michael Turquette, linux-arm-kernel, linux-clk, linux-kernel,
linux-sunxi
Hi Stephen,
On 8/15/22 12:26, Stephen Boyd wrote:
> Quoting Samuel Holland (2022-08-09 18:40:24)
>> ccu_mp_find_best() already computes a best_rate at the same time as the
>> best m and p factors. Return it so the caller does not need to duplicate
>> the division.
>
> Did the compiler figure this out and thus this patch makes no difference
> to the final object code?
It makes a difference at least on my gcc version 11.1.0.
Before:
text data bss dec hex filename
18257 12 0 18269 475d drivers/clk/sunxi-ng/sunxi-ccu.o
After:
text data bss dec hex filename
18083 12 0 18095 46af drivers/clk/sunxi-ng/sunxi-ccu.o
I will send a v2 covering all of the CCU clock types.
Regards,
Samuel
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] clk: sunxi-ng: mp: Avoid computing the rate twice
@ 2022-12-31 17:21 ` Samuel Holland
0 siblings, 0 replies; 8+ messages in thread
From: Samuel Holland @ 2022-12-31 17:21 UTC (permalink / raw)
To: Stephen Boyd, Chen-Yu Tsai, Jernej Skrabec
Cc: Michael Turquette, linux-arm-kernel, linux-clk, linux-kernel,
linux-sunxi
Hi Stephen,
On 8/15/22 12:26, Stephen Boyd wrote:
> Quoting Samuel Holland (2022-08-09 18:40:24)
>> ccu_mp_find_best() already computes a best_rate at the same time as the
>> best m and p factors. Return it so the caller does not need to duplicate
>> the division.
>
> Did the compiler figure this out and thus this patch makes no difference
> to the final object code?
It makes a difference at least on my gcc version 11.1.0.
Before:
text data bss dec hex filename
18257 12 0 18269 475d drivers/clk/sunxi-ng/sunxi-ccu.o
After:
text data bss dec hex filename
18083 12 0 18095 46af drivers/clk/sunxi-ng/sunxi-ccu.o
I will send a v2 covering all of the CCU clock types.
Regards,
Samuel
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2022-12-31 17:23 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-08-10 1:40 [PATCH] clk: sunxi-ng: mp: Avoid computing the rate twice Samuel Holland
2022-08-10 1:40 ` Samuel Holland
2022-08-14 10:02 ` Jernej Škrabec
2022-08-14 10:02 ` Jernej Škrabec
2022-08-15 17:26 ` Stephen Boyd
2022-08-15 17:26 ` Stephen Boyd
2022-12-31 17:21 ` Samuel Holland
2022-12-31 17:21 ` Samuel Holland
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