[PATCH v3 5/5] cpufreq: qoriq: Don't look at clock implementation details

Li Yang leoli at freescale.com
Sat Feb 27 08:01:41 AEDT 2016


On Fri, Feb 26, 2016 at 12:16 PM, Scott Wood <oss at buserror.net> wrote:
> On Fri, 2016-02-26 at 12:14 -0600, Li Yang wrote:
>> On Fri, Sep 25, 2015 at 4:50 PM, Rafael J. Wysocki <rjw at rjwysocki.net>
>> wrote:
>> > On Friday, September 25, 2015 04:17:07 PM Scott Wood wrote:
>> > > On Fri, 2015-09-25 at 23:42 +0200, Rafael J. Wysocki wrote:
>> > > > On Tuesday, September 22, 2015 12:46:54 PM Viresh Kumar wrote:
>> > > > > On 19-09-15, 23:29, Scott Wood wrote:
>> > > > > > Get the CPU clock's potential parent clocks from the clock
>> > > > > > interface
>> > > > > > itself, rather than manually parsing the clocks property to find a
>> > > > > > phandle, looking at the clock-names property of that, and assuming
>> > > > > > that
>> > > > > > those are valid parent clocks for the cpu clock.
>> > > > > >
>> > > > > > This is necessary now that the clocks are generated based on the
>> > > > > > clock
>> > > > > > driver's knowledge of the chip rather than a fragile device-tree
>> > > > > > description of the mux options.
>> > > > > >
>> > > > > > We can now rely on the clock driver to ensure that the mux only
>> > > > > > exposes
>> > > > > > options that are valid.  The cpufreq driver was currently being
>> > > > > > overly
>> > > > > > conservative in some cases -- for example, the "min_cpufreq =
>> > > > > > get_bus_freq()" restriction only applies to chips with erratum
>> > > > > > A-004510, and whether the freq_mask used on p5020 is needed
>> > > > > > depends on
>> > > > > > the actual frequencies of the PLLs (FWIW, p5040 has a similar
>> > > > > > limitation but its .freq_mask was zero) -- and the frequency mask
>> > > > > > mechanism made assumptions about particular parent clock indices
>> > > > > > that
>> > > > > > are no longer valid.
>> > > > > >
>> > > > > > Signed-off-by: Scott Wood <scottwood at freescale.com>
>> > > > > > ---
>> > > > > > v3: was patch 1/5 and patch 4/5, plus blacklist e6500 and changes
>> > > > > > to clk api usage
>> > > > > >
>> > > > > >  drivers/cpufreq/qoriq-cpufreq.c | 137 ++++++++++++---------------
>> > > > > > ------
>> > > > > > -------
>> > > > > >  1 file changed, 40 insertions(+), 97 deletions(-)
>> > > > >
>> > > > > Acked-by: Viresh Kumar <viresh.kumar at linaro.org>
>> > > >
>> > > > I'm wondering who's supposed to be merging this set?
>> > >
>> > > As I noted in the cover letter, I'm looking for acks so that I can apply
>> > > these to a topic branch which can be pulled through the PPC and ARM
>> > > trees,
>> > > each of which will have patches that depend on it.
>> >
>> > OK, so no objections from the cpufreq side and you have the ACK from
>> > Viresh.
>>
>> Hi Scott,
>>
>> Did you drop this patch later?  I can not find it in 4.5-rc still.
>
> I was asked to get an ack from Russell King patch 4/5, which this patch
> requires.  Despite repeated pings, I could not get a reply from Russell King.

This patch?   I think you should try to get ACK from clock maintainers
instead of Russell.

Commit fc4a05d4b0eb ("clk: Remove unused provider APIs") removed
__clk_get_num_parents() and clk_hw_get_parent_by_index(), leaving only
true provider API versions that operate on struct clk_hw.

qoriq-cpufreq needs these functions in order to determine the options
it has for calling clk_set_parent() and thus populate the cpufreq
table, so revive them as legitimate consumer APIs.

Signed-off-by: Scott Wood <scottwood at freescale.com>
---
v3: new patch

 drivers/clk/clk.c   | 19 +++++++++++++++++++
 include/linux/clk.h | 31 +++++++++++++++++++++++++++++++
 2 files changed, 50 insertions(+)

Regards,
Leo


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