Quoting Gregory CLEMENT (2018-07-13 03:27:26)

The return value of the get_parent operation is a u8, whereas a -EINVAL
was returned. This wrong value was return if the value was bigger that
the number of parent but this case was already handled by the core.

So we can just remove this chunk of code to fix the issue.

Reported-by: Dan Carpenter <redacted>
Fixes: 9818a7a4fd10 ("clk: mvebu: armada-37xx-periph: prepare cpu clk to
be used with DVFS")
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---

Applied to clk-next

This is actually a good point I've never considered. We should go fix
all the drivers that return a negative value to return a number that's
greater than the number of clks that are the parents and then we can
still get 'errors' from this clk_op.