kernel/linux.git/drivers/opp/core.c, branch v6.18.21

OPP: Return correct value in dev_pm_opp_get_level

2026-02-26T22:59:00+00:00

[ Upstream commit 0b7277e02dabba2a9921a7f4761ae6e627e7297a ] Commit 073d3d2ca7d4 ("OPP: Level zero is valid") modified the documentation for this function to indicate that errors should return a non-zero value to avoid colliding with the OPP level zero, however forgot to actually update the return. No in-tree kernel code depends on the error value being 0. Fixes: 073d3d2ca7d4 ("OPP: Level zero is valid") Signed-off-by: Aleks Todorov Signed-off-by: Viresh Kumar Signed-off-by: Sasha Levin

OPP: Add support to find OPP for a set of keys

2025-08-26T05:10:58+00:00

Some clients, such as PCIe, may operate at the same clock frequency across different data rates by varying link width. In such cases, frequency alone is not sufficient to uniquely identify an OPP. To support these scenarios, introduce a new API dev_pm_opp_find_key_exact() that allows OPP lookup with different set of keys like freq, level & bandwidth. Signed-off-by: Krishna Chaitanya Chundru [ Viresh: Minor cleanups ] Signed-off-by: Viresh Kumar

OPP: switch to use kmemdup_array()

2025-05-19T10:07:53+00:00

Use kmemdup_array() to avoid multiplication and possible overflows. Signed-off-by: Zhang Enpei Signed-off-by: Viresh Kumar

OPP: Use mutex locking guards

2025-05-02T05:25:52+00:00

Use mutex locking guard in the OPP core. No intentional functional impact. Signed-off-by: Viresh Kumar

OPP: Define and use scope-based cleanup helpers

2025-05-02T05:25:40+00:00

Define and use scope-based cleanup helpers for `struct opp` and `struct opp_table`. No intentional functional impact. Signed-off-by: Viresh Kumar

OPP: Return opp_table from dev_pm_opp_get_opp_table_ref()

2025-04-24T10:35:56+00:00

For convenience of users, return back the pointer to the opp_table from dev_pm_opp_get_opp_table_ref(), so they can do: opp_table = dev_pm_opp_get_opp_table_ref(tmp_table); No intentional functional impact. Signed-off-by: Viresh Kumar

OPP: Return opp from dev_pm_opp_get()

2025-04-24T10:35:53+00:00

For convenience of users, return back the pointer to the opp from dev_pm_opp_get(), so they can do: opp = dev_pm_opp_get(tmp_opp); No intentional functional impact. Signed-off-by: Viresh Kumar

OPP: Remove _get_opp_table_kref()

2025-04-24T10:35:33+00:00

Use dev_pm_opp_get_opp_table_ref() directly instead. No intentional functional impact. Signed-off-by: Viresh Kumar

PM / OPP: Add reference counting helpers for Rust implementation

2025-01-20T03:35:51+00:00

To ensure that resources such as OPP tables or OPP nodes are not freed while in use by the Rust implementation, it is necessary to increment their reference count from Rust code. This commit introduces a new helper function, dev_pm_opp_get_opp_table_ref(), to increment the reference count of an OPP table and declares the existing helper dev_pm_opp_get() in pm_opp.h. Signed-off-by: Viresh Kumar

OPP: fix dev_pm_opp_find_bw_*() when bandwidth table not initialized

2024-12-23T10:57:24+00:00

If a driver calls dev_pm_opp_find_bw_ceil/floor() the retrieve bandwidth from the OPP table but the bandwidth table was not created because the interconnect properties were missing in the OPP consumer node, the kernel will crash with: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004 ... pc : _read_bw+0x8/0x10 lr : _opp_table_find_key+0x9c/0x174 ... Call trace: _read_bw+0x8/0x10 (P) _opp_table_find_key+0x9c/0x174 (L) _find_key+0x98/0x168 dev_pm_opp_find_bw_ceil+0x50/0x88 ... In order to fix the crash, create an assert function to check if the bandwidth table was created before trying to get a bandwidth with _read_bw(). Fixes: add1dc094a74 ("OPP: Use generic key finding helpers for bandwidth key") Signed-off-by: Neil Armstrong Signed-off-by: Viresh Kumar