Messages in this thread | | | Date | Wed, 27 Mar 2013 15:25:24 +0530 | Subject | Re: [PATCH v4] clk: allow reentrant calls into the clk framework | From | Viresh Kumar <> |
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On 27 March 2013 15:10, Thomas Gleixner <tglx@linutronix.de> wrote: > On Wed, 27 Mar 2013, Mike Turquette wrote: > >> Reentrancy into the clock framework from the clk.h api is necessary >> for clocks that are prepared and unprepared via i2c_transfer (which >> includes many PMICs and discrete audio chips) as well as for several >> other use cases. > > That explanation sucks. > > Why does an i2c clock need reentrancy? Just because it's i2c or what?
I am noway connected to this development but was just going through your mail and i think i might know the answer why is this required.
Consider an example where an external chip has clock controller and has bits which can be programmed to enable/disable clock. And this chip is connected via spi/i2c to SoC.
clk_prepare(peripheral on external chip) -> i2c_xfer(to write to external chips register) -> clk_enable(i2c controller) ->controller-xfer-routine.. and finally we enable clk here...
Sorry if i am on the wrong side :)
-- viresh
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