On 12/28, Masahiro Yamada wrote: > Currently, clk_register() never checks a circular parent looping, > but clock providers could register such an insane clock topology. > For example, "clk_a" could have "clk_b" as a parent, and vice versa. > In this case, clk_core_reparent() creates a circular parent list > and __clk_recalc_accuracies() calls itself recursively forever. > > The core infrastructure should be kind enough to bail out, showing > an appropriate error message in such a case. This helps to easily > find a bug in clock providers. (uh, I made such a silly mistake > when I was implementing my clock providers first. I was upset > because the kernel did not respond, without any error message.) > > This commit adds a new helper function, __clk_is_ancestor(). It > returns true if the second argument is a possible ancestor of the > first one. If a clock core is a possible ancestor of itself, it > would make a loop when it were registered. That should be detected > as an error. > > Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com> > ---
Applied to clk-next -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
