kernel/linux.git/drivers/regulator/core.c, branch v6.1.177

regulator: core: fix locking in regulator_resolve_supply() error path

2026-07-04T11:41:28+00:00

commit 497330b203d2c59c5ff3fa4c34d14494d7203bc3 upstream. If late enabling of a supply regulator fails in regulator_resolve_supply(), the code currently triggers a lockdep warning: WARNING: drivers/regulator/core.c:2649 at _regulator_put+0x80/0xa0, CPU#6: kworker/u32:4/596 ... Call trace: _regulator_put+0x80/0xa0 (P) regulator_resolve_supply+0x7cc/0xbe0 regulator_register_resolve_supply+0x28/0xb8 as the regulator_list_mutex must be held when calling _regulator_put(). To solve this, simply switch to using regulator_put(). While at it, we should also make sure that no concurrent access happens to our rdev while we clear out the supply pointer. Add appropriate locking to ensure that. While the code in question will be removed altogether in a follow-up commit, I believe it is still beneficial to have this corrected before removal for future reference. Fixes: 36a1f1b6ddc6 ("regulator: core: Fix memory leak in regulator_resolve_supply()") Fixes: 8e5356a73604 ("regulator: core: Clear the supply pointer if enabling fails") Signed-off-by: André Draszik Link: https://patch.msgid.link/20260109-regulators-defer-v2-2-1a25dc968e60@linaro.org Signed-off-by: Mark Brown Signed-off-by: Nazar Kalashnikov Signed-off-by: Greg Kroah-Hartman

regulator: core: move supply check earlier in set_machine_constraints()

2026-03-04T12:19:37+00:00

[ Upstream commit 86a8eeb0e913f4b6a55dabba5122098d4e805e55 ] Since commit 98e48cd9283d ("regulator: core: resolve supply for boot-on/always-on regulators"), set_machine_constraints() can return -EPROBE_DEFER very late, after it has done a lot of work and configuration of the regulator. This means that configuration will happen multiple times for no benefit in that case. Furthermore, this can lead to timing-dependent voltage glitches as mentioned e.g. in commit 8a866d527ac0 ("regulator: core: Resolve supply name earlier to prevent double-init"). We can know that it's going to fail very early, in particular before going through the complete regulator configuration by moving some code around a little. Do so to avoid re-configuring the regulator multiple times, also avoiding the voltage glitches if we can. Fixes: 98e48cd9283d ("regulator: core: resolve supply for boot-on/always-on regulators") Signed-off-by: André Draszik Link: https://patch.msgid.link/20260109-regulators-defer-v2-3-1a25dc968e60@linaro.org Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regulator: core: Protect regulator_supply_alias_list with regulator_list_mutex

2026-01-11T14:18:32+00:00

[ Upstream commit 0cc15a10c3b4ab14cd71b779fd5c9ca0cb2bc30d ] regulator_supply_alias_list was accessed without any locking in regulator_supply_alias(), regulator_register_supply_alias(), and regulator_unregister_supply_alias(). Concurrent registration, unregistration and lookups can race, leading to: 1 use-after-free if an alias entry is removed while being read, 2 duplicate entries when two threads register the same alias, 3 inconsistent alias mappings observed by consumers. Protect all traversals, insertions and deletions on regulator_supply_alias_list with the existing regulator_list_mutex. Fixes: a06ccd9c3785f ("regulator: core: Add ability to create a lookup alias for supply") Signed-off-by: sparkhuang Reviewed-by: Charles Keepax Link: https://patch.msgid.link/20251127025716.5440-1-huangshaobo3@xiaomi.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regulator: core: disable supply if enabling main regulator fails

2026-01-11T14:18:22+00:00

[ Upstream commit fb1ebb10468da414d57153ddebaab29c38ef1a78 ] For 'always-on' and 'boot-on' regulators, the set_machine_constraints() may enable supply before enabling the main regulator, however if the latter fails, the function returns with an error but the supply remains enabled. When this happens, the regulator_register() function continues on the error path where it puts the supply regulator. Since enabling the supply is not balanced with a disable call, a warning similar to the following gets issued from _regulator_put(): [ 1.603889] WARNING: CPU: 2 PID: 44 at _regulator_put+0x8c/0xa0 [ 1.603908] Modules linked in: [ 1.603926] CPU: 2 UID: 0 PID: 44 Comm: kworker/u16:3 Not tainted 6.18.0-rc4 #0 NONE [ 1.603938] Hardware name: Qualcomm Technologies, Inc. IPQ9574/AP-AL02-C7 (DT) [ 1.603945] Workqueue: async async_run_entry_fn [ 1.603958] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 1.603967] pc : _regulator_put+0x8c/0xa0 [ 1.603976] lr : _regulator_put+0x7c/0xa0 ... [ 1.604140] Call trace: [ 1.604145] _regulator_put+0x8c/0xa0 (P) [ 1.604156] regulator_register+0x2ec/0xbf0 [ 1.604166] devm_regulator_register+0x60/0xb0 [ 1.604178] rpm_reg_probe+0x120/0x208 [ 1.604187] platform_probe+0x64/0xa8 ... In order to avoid this, change the set_machine_constraints() function to disable the supply if enabling the main regulator fails. Fixes: 05f224ca6693 ("regulator: core: Clean enabling always-on regulators + their supplies") Signed-off-by: Gabor Juhos Link: https://patch.msgid.link/20251107-regulator-disable-supply-v1-1-c95f0536f1b5@gmail.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regulator: core: fix NULL dereference on unbind due to stale coupling data

2025-08-15T10:04:45+00:00

[ Upstream commit ca46946a482238b0cdea459fb82fc837fb36260e ] Failing to reset coupling_desc.n_coupled after freeing coupled_rdevs can lead to NULL pointer dereference when regulators are accessed post-unbind. This can happen during runtime PM or other regulator operations that rely on coupling metadata. For example, on ridesx4, unbinding the 'reg-dummy' platform device triggers a panic in regulator_lock_recursive() due to stale coupling state. Ensure n_coupled is set to 0 to prevent access to invalid pointers. Signed-off-by: Alessandro Carminati Link: https://patch.msgid.link/20250626083809.314842-1-acarmina@redhat.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regulator: check that dummy regulator has been probed before using it

2025-03-28T20:59:00+00:00

commit 2c7a50bec4958f1d1c84d19cde518d0e96a676fd upstream. Due to asynchronous driver probing there is a chance that the dummy regulator hasn't already been probed when first accessing it. Cc: stable@vger.kernel.org Signed-off-by: Christian Eggers Link: https://patch.msgid.link/20250313103051.32430-3-ceggers@arri.de Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

regulator: core: Add missing newline character

2025-02-21T12:49:21+00:00

[ Upstream commit 155c569fa4c3b340fbf8571a0e42dd415c025377 ] dev_err_probe() error messages need newline character. Fixes: 6eabfc018e8d ("regulator: core: Allow specifying an initial load w/ the bulk API") Signed-off-by: Alexander Stein Link: https://patch.msgid.link/20250122072019.1926093-1-alexander.stein@ew.tq-group.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regulator: core: Fix modpost error "regulator_get_regmap" undefined

2024-06-27T11:46:20+00:00

[ Upstream commit 3f60497c658d2072714d097a177612d34b34aa3d ] Fix the modpost error "regulator_get_regmap" undefined by adding export symbol. Fixes: 04eca28cde52 ("regulator: Add helpers for low-level register access") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202406110117.mk5UR3VZ-lkp@intel.com Signed-off-by: Biju Das Link: https://lore.kernel.org/r/20240610195532.175942-1-biju.das.jz@bp.renesas.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regulator: core: fix debugfs creation regression

2024-05-17T09:56:22+00:00

commit 2a4b49bb58123bad6ec0e07b02845f74c23d5e04 upstream. regulator_get() may sometimes be called more than once for the same consumer device, something which before commit dbe954d8f163 ("regulator: core: Avoid debugfs: Directory ... already present! error") resulted in errors being logged. A couple of recent commits broke the handling of such cases so that attributes are now erroneously created in the debugfs root directory the second time a regulator is requested and the log is filled with errors like: debugfs: File 'uA_load' in directory '/' already present! debugfs: File 'min_uV' in directory '/' already present! debugfs: File 'max_uV' in directory '/' already present! debugfs: File 'constraint_flags' in directory '/' already present! on any further calls. Fixes: 2715bb11cfff ("regulator: core: Fix more error checking for debugfs_create_dir()") Fixes: 08880713ceec ("regulator: core: Streamline debugfs operations") Cc: stable@vger.kernel.org Cc: Geert Uytterhoeven Signed-off-by: Johan Hovold Link: https://lore.kernel.org/r/20240509133304.8883-1-johan+linaro@kernel.org Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

regulator: core: Only increment use_count when enable_count changes

2024-02-05T20:12:47+00:00

[ Upstream commit 7993d3a9c34f609c02171e115fd12c10e2105ff4 ] The use_count of a regulator should only be incremented when the enable_count changes from 0 to 1. Similarly, the use_count should only be decremented when the enable_count changes from 1 to 0. In the previous implementation, use_count was sometimes decremented to 0 when some consumer called unbalanced disable, leading to unexpected disable even the regulator is enabled by other consumers. With this change, the use_count accurately reflects the number of users which the regulator is enabled. This should make things more robust in the case where a consumer does leak references. Signed-off-by: Rui Zhang Link: https://lore.kernel.org/r/20231103074231.8031-1-zr.zhang@vivo.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin