Messages in this thread | | | Subject | Re: [PATCH v2 1/2] clk: fractional-divider: switch to rational best approximation | From | Andy Shevchenko <> | Date | Tue, 31 Mar 2015 12:33:03 +0300 |
| |
On Tue, 2015-03-31 at 10:42 +0300, Andy Shevchenko wrote: > On Tue, Mar 31, 2015 at 3:32 AM, Stephen Boyd <sboyd@codeaurora.org> wrote: > > On 03/30/15 11:57, Andy Shevchenko wrote: > >> This patch converts the code to use rational best approximation algorithm which > >> is more precise. > > >> --- a/drivers/clk/Kconfig > >> +++ b/drivers/clk/Kconfig > >> @@ -14,6 +14,7 @@ config COMMON_CLK > >> select HAVE_CLK_PREPARE > >> select CLKDEV_LOOKUP > >> select SRCU > >> + select RATIONAL > >> ---help--- > >> The common clock framework is a single definition of struct > >> clk, useful across many platforms, as well as an > >> @@ -63,7 +64,6 @@ config COMMON_CLK_SI5351 > >> tristate "Clock driver for SiLabs 5351A/B/C" > >> depends on I2C > >> select REGMAP_I2C > >> - select RATIONAL > >> ---help--- > >> This driver supports Silicon Labs 5351A/B/C programmable clock > >> generators. > >> @@ -139,7 +139,6 @@ config COMMON_CLK_CDCE706 > >> tristate "Clock driver for TI CDCE706 clock synthesizer" > >> depends on I2C > >> select REGMAP_I2C > >> - select RATIONAL > >> ---help--- > >> This driver supports TI CDCE706 programmable 3-PLL clock synthesizer. > > > > Will some kernel janitor find us if we leave the selects here? I know > > you removed it because COMMON_CLK must be Y here and we'd always select > > RATIONAL, but it feels better to leave it alone and actually split off > > the basic clock types into individual configs so that the tiny kernel > > users don't have unused code lying around. That could be future work > > someday and then we might forget to select RATIONAL again. > > I'm fine with that as well. So, do I need to resend or you apply > modified version?
There are couple of issues with arithmetics, such as we can't use mult_frac() because of potential overflow on 32 bit kernels, so I will resend new version.
-- Andy Shevchenko <andriy.shevchenko@intel.com> Intel Finland Oy
| |