Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1344858

Re: [PATCH v2] clk: check the actual phase if get_phase is provided

Show all headers | View raw

On 02/26, Shawn Lin wrote:
> On 2016/2/26 7:14, Stephen Boyd wrote:
> >On 02/18, Shawn Lin wrote:
> >>set_phase does sanity checking of degree and ask sub-driver
> 
> [...]
> 
> >>already there.
> >>
> >>Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
> >>
> >>---
> >
> >Knee jerk reaction is why does the provider code set a phase that
> >isn't requested? Do we need some sort of clk_round_phase() API
> >that parallels clk_round_rate() so that drivers know what phase
> >they're going to get? Or do drivers not care what phase they get
> >when they call clk_set_phase()?
> 
> Hi Stephen,
> 
> drivers should care what phase they get when calling clk_set_phase(i.e
> the drivers setting phase to do tuning work should know what the actual
> degrees is, which is important for them to decide the sample window
> algorithm).
> 
> By looking into the two drivers who use set_phase/get_phase pair
> currently, they actually both don'e care what the actual degrees when
> they call clk_set_phase. I think that is because the drivers are used
> for specific platform which support 0~360 implicitly. But the situation
> is NOT always right for cross-platform drivers. So add some sort of
> round_phase API is probably sane ?
> 

Do you have such a platform or driver though? I'd rather not do
anything unless we actually need to.

-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
a Linux Foundation Collaborative Project

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Re: [PATCH v2] clk: check the actual phase if get_phase is provided Stephen Boyd <sboyd@codeaurora.org> - 2016-02-26 00:20 +0100
  Re: [PATCH v2] clk: check the actual phase if get_phase is provided Shawn Lin <shawn.lin@rock-chips.com> - 2016-02-26 02:30 +0100
    Re: [PATCH v2] clk: check the actual phase if get_phase is provided Stephen Boyd <sboyd@codeaurora.org> - 2016-02-27 01:20 +0100
      Re: [PATCH v2] clk: check the actual phase if get_phase is provided Shawn Lin <shawn.lin@rock-chips.com> - 2016-02-29 02:20 +0100

csiph-web