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* clk: tests: Add tests for notifiersMaxime Ripard2022-10-101-0/+156
| | | | | | | | | | | | | | We're recently encountered a regression due to the rates reported through the clk_notifier_data being off when changing parents. Let's add a test suite and a test to make sure that we do get notified and with the proper rates. Suggested-by: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Maxime Ripard <maxime@cerno.tech> Link: https://lore.kernel.org/r/20221010-rpi-clk-fixes-again-v1-2-d87ba82ac404@cerno.tech Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
* clk: tests: Add missing test case for rangesMaxime Ripard2022-09-151-0/+53
| | | | | | | | | | | | Let's add a test on the rate range after a reparenting. This fails for now, but it's worth having it to document the corner cases we don't support yet. Signed-off-by: Maxime Ripard <maxime@cerno.tech> Link: https://lore.kernel.org/r/20220816112530.1837489-26-maxime@cerno.tech Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
* clk: Stop forwarding clk_rate_requests to the parentMaxime Ripard2022-09-151-0/+182
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the clock cannot modify its rate and has CLK_SET_RATE_PARENT, clk_mux_determine_rate_flags(), clk_core_round_rate_nolock() and a number of drivers will forward the clk_rate_request to the parent clock. clk_core_round_rate_nolock() will pass the pointer directly, which means that we pass a clk_rate_request to the parent that has the rate, min_rate and max_rate of the child, and the best_parent_rate and best_parent_hw fields will be relative to the child as well, so will point to our current clock and its rate. The most common case for CLK_SET_RATE_PARENT is that the child and parent clock rates will be equal, so the rate field isn't a worry, but the other fields are. Similarly, if the parent clock driver ever modifies the best_parent_rate or best_parent_hw, this will be applied to the child once the call to clk_core_round_rate_nolock() is done. best_parent_hw is probably not going to be a valid parent, and best_parent_rate might lead to a parent rate change different to the one that was initially computed. clk_mux_determine_rate_flags() and the affected drivers will copy the request before forwarding it to the parents, so they won't be affected by the latter issue, but the former is still going to be there and will lead to erroneous data and context being passed to the various clock drivers in the same sub-tree. Let's create two new functions, clk_core_forward_rate_req() and clk_hw_forward_rate_request() for the framework and the clock providers that will copy a request from a child clock and update the context to match the parent's. We also update the relevant call sites in the framework and drivers to use that new function. Let's also add a test to make sure we avoid regressions there. 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/20220816112530.1837489-22-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>
* clk: Introduce clk_core_has_parent()Maxime Ripard2022-09-151-0/+43
| | | | | | | | | | | | | | | | | | | We will need to know if a clk_core pointer has a given parent in other functions, so let's create a clk_core_has_parent() function that clk_has_parent() will call into. For good measure, let's add some unit tests as well to make sure it works properly. 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/20220816112530.1837489-20-maxime@cerno.tech Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> [sboyd@kernel.org: Move tmp declaration, fix conditional to check for current parent] Signed-off-by: Stephen Boyd <sboyd@kernel.org>
* clk: Set req_rate on reparentingMaxime Ripard2022-09-151-0/+239
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a non-rate clock started by default with a parent that never registered, core->req_rate will be 0. The expectation is that whenever the parent will be registered, req_rate will be updated with the new value that has just been computed. However, if that clock is a mux, clk_set_parent() can also make that clock no longer orphan. In this case however, we never update req_rate. The natural solution to this would be to update core->rate and core->req_rate in clk_reparent() by calling clk_recalc(). However, this doesn't work in all cases. Indeed, clk_recalc() is called by __clk_set_parent_before(), __clk_set_parent() and clk_core_reparent(). Both __clk_set_parent_before() and __clk_set_parent will call clk_recalc() with the enable_lock taken through a call to clk_enable_lock(), the underlying locking primitive being a spinlock. clk_recalc() calls the backing driver .recalc_rate hook, and that implementation might sleep if the underlying device uses a bus with accesses that might sleep, such as i2c. In such a situation, we would end up sleeping while holding a spinlock, and thus in an atomic section. In order to work around this, we can move the core->rate and core->req_rate update to the clk_recalc() calling sites, after the enable_lock has been released if it was taken. The only situation that could still be problematic is the clk_core_reparent() -> clk_reparent() case that doesn't have any locking. clk_core_reparent() is itself called by clk_hw_reparent(), which is then called by 4 drivers: * clk-stm32mp1.c, stm32/clk-stm32-core.c and tegra/clk-tegra210-emc.c use it in their set_parent implementation. The set_parent hook is only called by __clk_set_parent() and clk_change_rate(), both of them calling it without the enable_lock taken. * clk/tegra/clk-tegra124-emc.c calls it as part of its set_rate implementation. set_rate is only called by clk_change_rate(), again without the enable_lock taken. In both cases we can't end up in a situation where the clk_hw_reparent() caller would hold a spinlock, so it seems like this is a good workaround. Let's also add some unit tests to make sure we cover the original 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/20220816112530.1837489-14-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>
* clk: Take into account uncached clocks in clk_set_rate_range()Maxime Ripard2022-09-151-0/+31
| | | | | | | | | | | | | | | | | | clk_set_rate_range() will use the last requested rate for the clock when it calls into the driver set_rate hook. However, if CLK_GET_RATE_NOCACHE is set on that clock, the last requested rate might not be matching the current rate of the clock. In such a case, let's read out the rate from the hardware and use that in our set_rate instead. 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/20220816112530.1837489-13-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>
* clk: tests: Add some tests for orphan with multiple parentsMaxime Ripard2022-09-151-0/+237
| | | | | | | | | | | | | | | | | | Let's leverage the dummy mux with multiple parents we have to create a mux whose default parent will never be registered, and thus will always be orphan by default. We can then create some tests to make sure that the clock API behaves properly in such a case, and that the transition to a non-orphan clock when we change the parent is done properly. 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/20220816112530.1837489-12-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>
* clk: tests: Add tests for mux with multiple parentsMaxime Ripard2022-09-151-0/+121
| | | | | | | | | | | | | | | | | We'll need to test a few corner cases that occur when we have a mux clock whose default parent is missing. For now, let's create the context structure and the trivial ops, along with a test suite that just tests trivial things for now, without considering the orphan case. 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/20220816112530.1837489-11-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>
* clk: tests: Add tests for single parent muxMaxime Ripard2022-09-151-9/+185
| | | | | | | | | | | | | | | | We have a few tests for a mux with a single parent, testing the case where it used to be orphan. Let's leverage most of the code but register the clock properly to test a few trivial things. 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/20220816112530.1837489-10-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>
* clk: tests: Add tests for uncached clockMaxime Ripard2022-09-151-1/+92
| | | | | | | | | | | | | | | | | | | 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>
* clk: tests: Add reference to the orphan mux bug reportMaxime Ripard2022-09-151-0/+3
| | | | | | | | | | | | | 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>
* clk: tests: Add test suites descriptionMaxime Ripard2022-09-151-0/+33
| | | | | | | | | | | | | | | | | 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>
* clk: Drop the rate range on clk_put()Maxime Ripard2022-09-151-0/+110
| | | | | | | | | | | | | | | | | | | | | | | | | | 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: c80ac50cbb37 ("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>
* clk: test: Switch to clk_hw_get_clkMaxime Ripard2022-09-151-19/+55
| | | | | | | | | | | | 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>
* Revert "clk: Drop the rate range on clk_put()"Stephen Boyd2022-04-021-108/+0
| | | | | | | | | | | | | | | | This reverts commit 7dabfa2bc4803eed83d6f22bd6f045495f40636b. 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
* clk: Drop the rate range on clk_put()Maxime Ripard2022-03-251-0/+108
| | | | | | | | | | | | | | | | | | | | | 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: c80ac50cbb37 ("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>
* clk: test: Test clk_set_rate_range on orphan muxMaxime Ripard2022-03-251-0/+105
| | | | | | | | | | | | | | | | | | | 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>
* clk: Add clk_drop_rangeMaxime Ripard2022-03-111-2/+2
| | | | | | | | | | | | 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>
* clk: Always set the rate on clk_set_range_rateMaxime Ripard2022-03-111-30/+24
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* clk: Always clamp the rounded rateMaxime Ripard2022-03-111-18/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* clk: Introduce Kunit Tests for the frameworkMaxime Ripard2022-03-111-0/+787
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>