Hi folks just a brief comment on this one: On Thu, 30 Apr 2015, Boris Brezillon wrote: > Clock rates are stored in an unsigned long field, but ->round_rate() > (which returns a rounded rate from a requested one) returns a long > value (errors are reported using negative error codes), which can lead > to long overflow if the clock rate exceed 2Ghz. > > Change ->round_rate() prototype to return 0 or an error code, and pass the > requested rate as a pointer so that it can be adjusted depending on > hardware capabilities. ... > diff --git a/Documentation/clk.txt b/Documentation/clk.txt > index 0e4f90a..fca8b7a 100644 > --- a/Documentation/clk.txt > +++ b/Documentation/clk.txt > @@ -68,8 +68,8 @@ the operations defined in clk.h: > int (*is_enabled)(struct clk_hw *hw); > unsigned long (*recalc_rate)(struct clk_hw *hw, > unsigned long parent_rate); > - long (*round_rate)(struct clk_hw *hw, > - unsigned long rate, > + int (*round_rate)(struct clk_hw *hw, > + unsigned long *rate, > unsigned long *parent_rate); > long (*determine_rate)(struct clk_hw *hw, > unsigned long rate, I'd suggest that we should probably go straight to 64-bit rates. There are already plenty of clock sources that can generate rates higher than 4GiHz. - Paul
