On 08/20/2013 10:30 PM, Russell King - ARM Linux wrote: > On Tue, Aug 20, 2013 at 07:34:20PM +0200, Sylwester Nawrocki wrote: >> +int __clk_get(struct clk *clk) >> +{ >> + if (WARN_ON((!clk))) >> + return 0; > > This changes the behaviour of clk_get() My bad, will remove that. >> + >> + if (!try_module_get(clk->owner)) >> + return 0; > > If you want this to be safe against NULL pointers, just do this: > > if (clk && !try_module_get(clk->owner)) > return 0; Ok, that should work too. >> + >> + return 1; >> +} >> +EXPORT_SYMBOL(__clk_get); >> + >> +void __clk_put(struct clk *clk) >> +{ >> + if (!clk || IS_ERR(clk)) >> + return; >> + >> + module_put(clk->owner); > > Calling clk_put() with an error-pointer should be a Bad Thing and something > that shouldn't be encouraged, so trapping it is probably unwise. So, just > do here: > > if (clk) > module_put(clk->owner); > > If we do have some callers of this with ERR pointers, then we could add: > > if (WARN_ON_ONCE(IS_ERR(clk))) > return; > > and remove it after a full kernel cycle or so. I wouldn't be surprised to see some callers with ERR pointers, since clk_put() has been mostly a no op. I'm inclined to leave such a check temporarily, let's see if it catches any issues. Thanks for review of the other patches.