Quoting Manivannan Sadhasivam (2019-09-16 09:14:41) > The new implementation for determining parent map uses multiple ways > to pass parent info. The order in which it gets processed depends on > the first available member. Hence, it is necessary to zero init the > clk_init_data struct so that the expected member gets processed correctly. > So, add a warning if multiple clk_init_data members are available during > clk registration. > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasi...@linaro.org> > --- > drivers/clk/clk.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index c0990703ce54..7d6d6984c979 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -3497,6 +3497,14 @@ static int clk_core_populate_parent_map(struct > clk_core *core) > if (!num_parents) > return 0; > > + /* > + * Check for non-zero initialized clk_init_data struct. This is > + * required because, we only require one of the (parent_names/ > + * parent_data/parent_hws) to be set at a time. Otherwise, the > + * current code would use first available member. > + */ > + WARN_ON((parent_names && parent_data) || (parent_names && > parent_hws)); > +
This will warn for many drivers because they set clk_init_data on the stack and assign parent_names but let junk from the stack be assigned to parent_data. The code uses parent_names first and then looks for parent_data or parent_hws because of this fact of life that we've never required clk_init_data to be initialized to all zero. > /* > * Avoid unnecessary string look-ups of clk_core's possible parents by > * having a cache of names/clk_hw pointers to clk_core pointers.
