The clock framework supports clocks that can have their rate changed
without the kernel knowing about it using the CLK_GET_RATE_NOCACHE flag.
As its name suggests, this flag turns off the rate caching in the clock
framework, reading out the rate from the hardware any time we need to
read it.
Let's add a couple of tests to make sure it works as intended.
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> # imx8mp
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> # exynos4210, meson g12b
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220816112530.1837489-9-maxime@cerno.tech
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Some more context might be useful for unit-tests covering a previously
reported bug, so let's add a link to the discussion for that bug.
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> # imx8mp
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> # exynos4210, meson g12b
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220816112530.1837489-8-maxime@cerno.tech
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
We start to have a few test suites, and we'll add more, so it will get
pretty confusing to figure out what is supposed to be tested in what
suite.
Let's add some comments to explain what setup they create, and what we
should be testing in every suite.
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> # imx8mp
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> # exynos4210, meson g12b
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220816112530.1837489-7-maxime@cerno.tech
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
When clk_put() is called we don't make another clk_set_rate() call to
re-evaluate the rate boundaries. This is unlike clk_set_rate_range()
that evaluates the rate again each time it is called.
However, clk_put() is essentially equivalent to clk_set_rate_range()
since after clk_put() completes the consumer's boundaries shouldn't be
enforced anymore.
Let's add a call to clk_set_rate_range() in clk_put() to make sure those
rate boundaries are dropped and the clock provider drivers can react. In
order to be as non-intrusive as possible, we'll just make that call if
the clock had non-default boundaries.
Also add a few tests to make sure this case is covered.
Fixes: c80ac50cbb ("clk: Always set the rate on clk_set_range_rate")
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com> # imx8mp
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> # exynos4210, meson g12b
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220816112530.1837489-3-maxime@cerno.tech
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Following the clk_hw->clk pointer is equivalent to calling
clk_hw_get_clk(), but will make the job harder if we need to rework that
part in the future.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220816112530.1837489-2-maxime@cerno.tech
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
This reverts commit 7dabfa2bc4. There are
multiple reports that this breaks boot on various systems. The common
theme is that orphan clks are having rates set on them when that isn't
expected. Let's revert it out for now so that -rc1 boots.
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: Tony Lindgren <tony@atomide.com>
Reported-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Link: https://lore.kernel.org/r/366a0232-bb4a-c357-6aa8-636e398e05eb@samsung.com
Cc: Maxime Ripard <maxime@cerno.tech>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20220403022818.39572-1-sboyd@kernel.org
When clk_put() is called we don't make another clk_set_rate() call to
re-evaluate the rate boundaries. This is unlike clk_set_rate_range()
that evaluates the rate again each time it is called.
However, clk_put() is essentially equivalent to clk_set_rate_range()
since after clk_put() completes the consumer's boundaries shouldn't be
enforced anymore.
Let's add a call to clk_set_rate_range() in clk_put() to make sure those
rate boundaries are dropped and the clock provider drivers can react.
Also add a few tests to make sure this case is covered.
Fixes: c80ac50cbb ("clk: Always set the rate on clk_set_range_rate")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220325161144.1901695-4-maxime@cerno.tech
[sboyd@kernel.org: Reword commit text]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
A bug recently affected the Tegra30 where calling clk_set_rate_range()
on a clock would make it change its rate to the minimum.
This was due to the clock in question being a mux that was orphan at
registration, which lead to the clk_core req_rate being 0, and the
clk_set_rate_range() function then calling clk_set_rate() with req_rate,
effectively making that clock running at the minimum rate allowed, even
though the initial rate was within that range.
Make a test suite to create a mux initially orphan, and then make sure
that if our clock rate was initially within a given range, then
enforcing that range won't affect it.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220325161144.1901695-3-maxime@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
In order to reset the range on a clock, we need to call
clk_set_rate_range with a minimum of 0 and a maximum of ULONG_MAX. Since
it's fairly inconvenient, let's introduce a clk_drop_range() function
that will do just this.
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220225143534.405820-8-maxime@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
When we change a clock minimum or maximum using clk_set_rate_range(),
clk_set_min_rate() or clk_set_max_rate(), the current code will only
trigger a new rate change if the rate is outside of the new boundaries.
However, a clock driver might want to always keep the clock rate to
one of its boundary, for example the minimum to keep the power
consumption as low as possible.
Since they don't always get called though, clock providers don't have the
opportunity to implement this behaviour.
Let's trigger a clk_set_rate() on the previous requested rate every time
clk_set_rate_range() is called. That way, providers that care about the
new boundaries have a chance to adjust the rate, while providers that
don't care about those new boundaries will return the same rate than
before, which will be ignored by clk_set_rate() and won't result in a
new rate change.
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220225143534.405820-7-maxime@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The current core while setting the min and max rate properly in the
clk_request structure will not make sure that the requested rate is
within these boundaries, leaving it to each and every driver to make
sure it is.
It's not clear if this was on purpose or not, but this introduces some
inconsistencies within the API.
For example, a user setting a range and then calling clk_round_rate()
with a value outside of that range will get the same value back
(ignoring any driver adjustements), effectively ignoring the range that
was just set.
Another one, arguably worse, is that it also makes clk_round_rate() and
clk_set_rate() behave differently if there's a range and the rate being
used for both is outside that range. As we have seen, the rate will be
returned unchanged by clk_round_rate(), but clk_set_rate() will error
out returning -EINVAL.
Let's make sure the framework will always clamp the rate to the current
range found on the clock, which will fix both these inconsistencies.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220225143534.405820-5-maxime@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.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>
Maxime Ripard