Re: [PATCH v2 2/2] clk: divider: Add some kunit test suites

Brian Masney
2026-04-17T19:27:05Z

On Fri, Apr 17, 2026 at 12:15 PM Lad, Prabhakar
<prabhakar.csengg@gmail.com> wrote:
> On Fri, Apr 17, 2026 at 2:21 PM Brian Masney <bmasney@redhat.com> wrote:
> > On Thu, Apr 16, 2026 at 5:35 PM Brian Masney <bmasney@redhat.com> wrote:
> > > On Mon, Apr 13, 2026 at 01:49:12PM +0100, Prabhakar wrote:
> > > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > > + /*
> > > > + * ULONG_MAX is the canonical way to probe the maximum rate a clock
> > > > + * can produce. With a parent at 1 GHz and the smallest table divider
> > > > + * being 2, the expected maximum is 500 MHz.
> > > > + *
> > > > + * Before the fix this returned 125 MHz (PARENT_RATE / 8), the
> > > > + * minimum rate, because the search loop was bypassed entirely.
> > >
> > > The "Before the fix" comment should go in the commit log. The comment in
> > > the code should describe how the code is right now.
> >
> > To demonstrate the existing issue, you could structure your series by:
> >
> > - Introduce the test as the first patch and have it show the issue and
> > the current behavior.
> > - Put the divider fix in, and update the test for the new behavior.
> >
> Sure to confirm,
>
> patch #1, have KUNIT_EXPECT_EQ() with a false positive.
> Patch #2: Clock divider fix + updated KUNIT_EXPECT_EQ() with correct
> expected values.

Yes, sounds good.

Hopefully the kunit change in the second patch is minimal. The issue
with having the kunit change for the fix in another patch is that
it'll break the tests if git bisect is used.

Brian