kernel/linux.git/drivers/opp/core.c, branch linux-4.20.y

OPP: Use opp_table->regulators to verify no regulator case

2019-02-12T19:02:18+00:00

[ Upstream commit 90e3577b5feb42bac1269e16bb3d2bdd8f6df40f ] The value of opp_table->regulator_count is not very consistent right now and it may end up being 0 while we do have a "opp-microvolt" property in the OPP table. It was kept that way as we used to check if any regulators are set with the OPP core for a device or not using value of regulator_count. Lets use opp_table->regulators for that purpose as the meaning of regulator_count is going to change in the later patches. Reported-by: Quentin Perret Signed-off-by: Viresh Kumar Signed-off-by: Sasha Levin

cpufreq: scpi/scmi: Fix freeing of dynamic OPPs

2019-01-16T21:03:20+00:00

commit 1690d8bb91e370ab772062b79bd434ce815c4729 upstream. Since the commit 2a4eb7358aba "OPP: Don't remove dynamic OPPs from _dev_pm_opp_remove_table()", dynamically created OPP aren't automatically removed anymore by dev_pm_opp_cpumask_remove_table(). This affects the scpi and scmi cpufreq drivers which no longer free OPPs on failures or on invocations of the policy->exit() callback. Create a generic OPP helper dev_pm_opp_remove_all_dynamic() which can be called from these drivers instead of dev_pm_opp_cpumask_remove_table(). In dev_pm_opp_remove_all_dynamic(), we need to make sure that the opp_list isn't getting accessed simultaneously from other parts of the OPP core while the helper is freeing dynamic OPPs, i.e. we can't drop the opp_table->lock while traversing through the OPP list. And to accomplish that, this patch also creates _opp_kref_release_unlocked() which can be called from this new helper with the opp_table lock already held. Cc: 4.20 # v4.20 Reported-by: Valentin Schneider Fixes: 2a4eb7358aba "OPP: Don't remove dynamic OPPs from _dev_pm_opp_remove_table()" Signed-off-by: Viresh Kumar Tested-by: Valentin Schneider Reviewed-by: Sudeep Holla Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

OPP: Return error on error from dev_pm_opp_get_opp_count()

2018-10-04T03:40:56+00:00

Return error number instead of 0 on failures. Fixes: a1e8c13600bf ("PM / OPP: "opp-hz" is optional for power domains") Signed-off-by: Viresh Kumar

OPP: Prevent creating multiple OPP tables for devices sharing OPP nodes

2018-10-01T09:30:31+00:00

When two or more devices are sharing their clock and voltage rails, they share the same OPP table. But there are some corner cases where the OPP core incorrectly creates separate OPP tables for them. For example, CPU 0 and 1 share clock/voltage rails. The platform specific code calls dev_pm_opp_set_regulators() for CPU0 and the OPP core creates an OPP table for it (the individual OPPs aren't initialized as of now). The same is repeated for CPU1 then. Because _opp_get_opp_table() doesn't compare DT node pointers currently, it fails to find the link between CPU0 and CPU1 and so creates a new OPP table. Fix this by calling _managed_opp() from _opp_get_opp_table(). _managed_opp() gain an additional argument (index) to get the right node pointer. This resulted in simplifying code in _of_add_opp_table_v2() as well. Tested-by: Niklas Cassel Signed-off-by: Viresh Kumar

OPP: Use a single mechanism to free the OPP table

2018-09-19T21:56:46+00:00

Currently there are two separate ways to free the OPP table based on how it is created in the first place. We call _dev_pm_opp_remove_table() to free the static and/or dynamic OPP, OPP list devices, etc. This is done for the case where the OPP table is added while initializing the OPPs, like via the path dev_pm_opp_of_add_table(). We also call dev_pm_opp_put_opp_table() in some cases which eventually frees the OPP table structure once the reference count reaches 0. This is used by the first case as well as other cases like dev_pm_opp_set_regulators() where the OPPs aren't necessarily initialized at this point. This whole thing is a bit unclear and messy and obstruct any further cleanup/fixup of OPP core. This patch tries to streamline this by keeping a single path for OPP table destruction, i.e. dev_pm_opp_put_opp_table(). All the cleanup happens in _opp_table_kref_release() now after the reference count reaches 0. _dev_pm_opp_remove_table() is removed as it isn't required anymore. We don't drop the reference to the OPP table after creating it from _of_add_opp_table_v{1|2}() anymore and the same is dropped only when we try to remove them. Tested-by: Niklas Cassel Signed-off-by: Viresh Kumar

OPP: Don't remove dynamic OPPs from _dev_pm_opp_remove_table()

2018-09-19T21:56:45+00:00

Only one platform was depending on this feature and it is already updated now. Stop removing dynamic OPPs from _dev_pm_opp_remove_table(). This simplifies lot of paths and removes unnecessary parameters. Tested-by: Niklas Cassel Signed-off-by: Viresh Kumar

OPP: Create separate kref for static OPPs list

2018-09-19T21:56:43+00:00

The static OPPs don't always get freed with the OPP table, it can happen before that as well. For example, if the OPP table is first created using helpers like dev_pm_opp_set_supported_hw() and the OPPs are created at a later point. Now when the OPPs are removed, the OPP table stays until the time dev_pm_opp_put_supported_hw() is called. Later patches will streamline the freeing of OPP table and that requires the static OPPs to get freed with help of a separate kernel reference. This patch prepares for that by creating a separate kref for static OPPs list. Tested-by: Niklas Cassel Signed-off-by: Viresh Kumar

OPP: Don't take OPP table's kref for static OPPs

2018-09-19T21:56:43+00:00

The reference count is only required to be incremented for every call that may lead to adding the OPP table. For static OPPs the same should be done from the parent routine which adds all static OPPs together and so only one refcount for all static OPPs. Update code to reflect that. The refcount is incremented every time a dynamic OPP is created (as that can lead to creating the OPP table) and the same is dropped when the OPP is removed. Tested-by: Niklas Cassel Signed-off-by: Viresh Kumar

OPP: Pass index to _of_init_opp_table()

2018-09-19T21:56:41+00:00

This is a preparatory patch required for the next commit which will start using OPP table's node pointer in _of_init_opp_table(), which requires the index in order to read the OPP table's phandle. This commit adds the index argument in the call chains in order to get it delivered to _of_init_opp_table(). Tested-by: Niklas Cassel Signed-off-by: Viresh Kumar

OPP: Protect dev_list with opp_table lock

2018-09-19T21:56:40+00:00

The dev_list needs to be protected with a lock, else we may have simultaneous access (addition/removal) to it and that would be racy. Extend scope of the opp_table lock to protect dev_list as well. Tested-by: Niklas Cassel Signed-off-by: Viresh Kumar