Hi Chander, On Tuesday 03 of September 2013 17:04:28 Chander Kashyap wrote: > Some platform has provision to change cpu parent clock during > cpu frequency scaling. This patch series provides a mechanism to > implement the same using CCF. > > Patch1 provides mechanism to migrate to new parent temporarily. > > Patch2 updates the user of clk_register_mux and DEFINE_CLK_MUX which are > modified to add support for clk migration. > > Patch3 adds support to Exynos5250 to use the clock parent migration > feature implemented in CCF. I don't really like this approach. A need to change mux setting temporarily is heavily platform-specific and I don't think it should be handled by generic code. First of all there are many factor that you would have to account for to make this solution generic, such as: - board specific alternative parents, - exact moment of parent change, - some other platform specific conditions, like CPU voltage that must be changed when mux is changed, because it changes CPU frequency, - and probably a lot of more factors that only people working with all the platforms supported (and unsupported yet) by Linux. I can see at least two solutions for this problem that don't require changing core code of common clock framework: 1) Implementing a special clock type using normal mux ops, but also registering a notifier for its PRE_RATE_CHANGE and POST_RATE_CHANGE events to perform parent switching. 2) Using normal mux clock, but registering such notifiers in clock controller or cpufreq driver. Best regards, Tomasz -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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