2013-08-07 07:53:05

by Bo Shen

[permalink] [raw]
Subject: [RFC PATCH] clock: correct the comparison parameter of MHz

correct the comparison parameter of MHz from 4,000,000 to 1,000,000

Signed-off-by: Bo Shen <[email protected]>

---
kernel/time/sched_clock.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
index a326f27..62885f7 100644
--- a/kernel/time/sched_clock.c
+++ b/kernel/time/sched_clock.c
@@ -128,7 +128,7 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate)
clocks_calc_mult_shift(&cd.mult, &cd.shift, rate, NSEC_PER_SEC, 0);

r = rate;
- if (r >= 4000000) {
+ if (r >= 1000000) {
r /= 1000000;
r_unit = 'M';
} else if (r >= 1000) {
--
1.7.9.5


2013-08-07 08:04:31

by Russell King - ARM Linux

[permalink] [raw]
Subject: Re: [RFC PATCH] clock: correct the comparison parameter of MHz

On Wed, Aug 07, 2013 at 03:47:40PM +0800, Bo Shen wrote:
> correct the comparison parameter of MHz from 4,000,000 to 1,000,000

You're assuming this wasn't intentional. As the division by 1000000
ends up losing the fractional rate, I decided to leave 1-4MHz as kHz,
so something like 1.832MHz would be displayed as 1832kHz and not
1MHz.

2013-08-07 08:08:24

by Bo Shen

[permalink] [raw]
Subject: Re: [RFC PATCH] clock: correct the comparison parameter of MHz

Hi Russell King,

On 8/7/2013 16:02, Russell King - ARM Linux wrote:
> On Wed, Aug 07, 2013 at 03:47:40PM +0800, Bo Shen wrote:
>> correct the comparison parameter of MHz from 4,000,000 to 1,000,000
>
> You're assuming this wasn't intentional. As the division by 1000000
> ends up losing the fractional rate, I decided to leave 1-4MHz as kHz,
> so something like 1.832MHz would be displayed as 1832kHz and not
> 1MHz.

Thanks for clarification of this. Now, it is better for me to understand
this piece of code.

Best Regards,
Bo Shen