On Fri, Jun 17, 2016 at 04:05:33PM -0700, Michael Turquette wrote: > Quoting Maxime Ripard (2016-05-16 05:47:01) > > A fixed factor clock, if it needs to change its rate, by definition do not > > have any choice but to modify its parent rate. > > Logically it makes sense to always propagate the rate-change request up > to the parent for a fixed-factor clock if we desire to change its rate. > However, I wonder if doing this for all users of fixed-factor-clock in > DT is safe? Some users may be counting on it not changing. > > There are 397 instances of fixed-factor-clock in .dts[i] today, so this > change worries me a bit. Understood. > > > > > Add the CLK_SET_RATE_PARENT flag to that clock so that it can happen > > > > Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> > > --- > > drivers/clk/clk-fixed-factor.c | 3 ++- > > 1 file changed, 2 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/clk/clk-fixed-factor.c b/drivers/clk/clk-fixed-factor.c > > index 75cd6c792cb8..3363abd9b4ae 100644 > > --- a/drivers/clk/clk-fixed-factor.c > > +++ b/drivers/clk/clk-fixed-factor.c > > @@ -167,7 +167,8 @@ void __init of_fixed_factor_clk_setup(struct device_node *node) > > of_property_read_string(node, "clock-output-names", &clk_name); > > parent_name = of_clk_get_parent_name(node, 0); > > > > - clk = clk_register_fixed_factor(NULL, clk_name, parent_name, 0, > > + clk = clk_register_fixed_factor(NULL, clk_name, parent_name, > > + CLK_SET_RATE_PARENT, > > An alternative would be to pass in the flags you want, somehow. For the > clock you are trying to fix, is it inside of the SoC or external? If it > is internal, and part of a larger clock controller driver, is this for > the legacy style allwinner clock drivers that put everything in DT? It is :( What we could do, is have an extra compatible for that clock (like "allwinner,sun4i-a10-pll3-x2" in that case), and set the flag only for that compatible. Would that work for you? > If not, it would better to initialize it statically and shove this > flag into the struct clk_init_data storage. Hopefully, yes, that should be addressed by the new framework, but I need reviews to get it merged ;) Thanks! Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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