Add KUnit tests to verify the behaviour of clk_divider_bestdiv() when
clk_round_rate() is called with ULONG_MAX, which is the canonical way
to probe the maximum rate a clock can produce.
Two test cases are introduced:
- clk_divider_bestdiv_ulong_max_returns_max_rate: registers a 1 GHz
fixed-rate parent driving a table-based divider whose smallest entry
is div=2 (entries: 2, 4, 8). Calls clk_hw_round_rate(div_hw, ULONG_MAX)
and checks the result.
- clk_divider_bestdiv_mux_ulong_max_returns_max_rate: places a two-input
mux (4 GHz and 2 GHz fixed-rate parents, CLK_SET_RATE_PARENT) ahead of
the same table-based divider to verify correct parent selection under
ULONG_MAX.
Both tests use an explicit clk_div_table with a minimum divider of 2 so
that the pre-loop maxdiv clamping in clk_divider_bestdiv():
maxdiv = min(ULONG_MAX / rate, maxdiv);
clamps maxdiv to 1, causing _next_div() to return 2 on the first
iteration and skip the loop body entirely. This makes bestdiv fall back
to the maximum divider, returning the minimum rate rather than the
maximum.
The expected values intentionally reflect the buggy output:
- test 1: PARENT_RATE_1GHZ / 8 (minimum rate, not maximum)
- test 2: 0 (invalid, loop never populated bestdiv)
These will be corrected to PARENT_RATE_1GHZ / 2 and PARENT_RATE_4GHZ / 2
respectively once the fix to clk_divider_bestdiv() is applied.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Brian Masney <bmasney@redhat.com>
Signed-off-by: Brian Masney <bmasney@redhat.com>
Some configurations want to enable CONFIG_KUNIT without enabling
CONFIG_OF_OVERLAY. The kunit overlay code already skips if
CONFIG_OF_OVERLAY isn't enabled, so these selects here aren't really
doing anything besides making it easier to run the tests without them
skipping. Remove the select and move the config setting to the
drivers/clk/.kunitconfig file so that the clk tests can be run with or
without CONFIG_OF_OVERLAY set to test either behavior.
Fixes: 5776526beb ("clk: Add KUnit tests for clk fixed rate basic type")
Fixes: 274aff8711 ("clk: Add KUnit tests for clks registered with struct clk_parent_data")
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20241016212738.897691-1-sboyd@kernel.org
Test that the fixed rate basic type clk works as intended.
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Cc: Rae Moar <rmoar@google.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20240718210513.3801024-8-sboyd@kernel.org
In light of the recent discovery that the fractional divisor
approximation does not utilize the full available range for clocks that
are flagged CLK_FRAC_DIVIDER_ZERO_BASED [1], implement tests for the
edge cases of this clock type.
Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
Link: https://lore.kernel.org/lkml/20230529133433.56215-1-frank@oltmanns.dev [1]
Link: https://lore.kernel.org/r/20230617131041.18313-3-frank@oltmanns.dev
[sboyd@kernel.org: Rename suite and tests slightly, drop unused
includes, store parent rate to compare instead of repeating equation]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
CONFIG_UML_PCI_OVER_VIRTIO=y is needed to enable CONFIG_PCI=y on UML.
However, this causes test failures when running the clk tests, i.e.
$ ./tools/testing/kunit/kunit.py run --kunitconfig=drivers/clk
A snippet of the particular error is:
> ok 1 - clk_gate_test_parent_rate
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 45 at lib/logic_iomem.c:141 __raw_readl+0x9f/0xd0
This is triggered by this cast in the test:
143 ctx->fake_mem = (void __force __iomem *)&ctx->fake_reg;
this seems to work except when logic iomem is enabled, i.e.
CONFIG_INDIRECT_IOMEM=y.
As a short-term fix, explicitly disable CONFIG_UML_PCI_OVER_VIRTIO in
drivers/clk/.kunitconfig so we can enable it for everyone else by
default in kunit.py.
The long-term fix probably requires something more complicated, like
#ifdef CONFIG_INDIRECT_IOMEM
logic_iomem_add_region(...);
#endif
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reported-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: David Gow <davidgow@google.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Let's test various parts of the rate-related clock API with the kunit
testing framework.
Cc: kunit-dev@googlegroups.com
Tested-by: Daniel Latypov <dlatypov@google.com>
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220225143534.405820-3-maxime@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Test various parts of the clk gate implementation with the kunit testing
framework.
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Daniel Latypov <dlatypov@google.com>
Cc: <kunit-dev@googlegroups.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220120175902.2165958-1-sboyd@kernel.org
