kernel/drivers/regulator/core.c, branch linux-5.1.y

regulator: core: Avoid potential deadlock on regulator_unregister

2019-05-31T13:43:37Z

[ Upstream commit 063773011d33bb36588a90385aa9eb75d13c6d80 ] Lockdep reports the following issue on my setup: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((work_completion)(&(&rdev->disable_work)->work)); lock(regulator_list_mutex); lock((work_completion)(&(&rdev->disable_work)->work)); lock(regulator_list_mutex); The problem is that regulator_unregister takes the regulator_list_mutex and then calls flush_work on disable_work. But regulator_disable_work calls regulator_lock_dependent which will also take the regulator_list_mutex. Resulting in a deadlock if the flush_work call actually needs to flush the work. Fix this issue by moving the flush_work outside of the regulator_list_mutex. The list mutex is not used to guard the point at which the delayed work is queued, so its use adds no additional safety. Fixes: f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking") Signed-off-by: Charles Keepax Reviewed-by: Dmitry Osipenko Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regulator: core: Actually put the gpiod after use

2019-05-31T13:43:22Z

[ Upstream commit 78927aa40bc82f32de07323ddc1c9de07ac68180 ] I went to great lengths to hand over the management of the GPIO descriptors to the regulator core, and some stray rebased oneliner in the old patch must have been assuming the devices were still doing devres management of it. We handed the management over to the regulator core, so of course the regulator core shall issue gpiod_put() when done. Sorry for the descriptor leak. Fixes: 541d052d7215 ("regulator: core: Only support passing enable GPIO descriptors") Signed-off-by: Linus Walleij Signed-off-by: Mark Brown Signed-off-by: Sasha Levin

regulator: core: fix error path for regulator_set_voltage_unlocked

2019-05-25T16:16:19Z

commit 70b464918e5331e488058870fcc6821d54c4e541 upstream. During several error paths in the function regulator_set_voltage_unlocked() the value of 'ret' can take on negative error values. However, in calls that go through the 'goto out' statement, this return value is lost and return 0 is used instead, indicating a 'pass'. There are several cases where this function should legitimately return a fail instead of a pass: one such case includes constraints check during voltage selection in the call to regulator_check_voltage(), which can have -EINVAL for the case when an unsupported voltage is incorrectly requested. In that case, -22 is expected as the return value, not 0. Fixes: 9243a195be7a ("regulator: core: Change voltage setting path") Cc: stable Signed-off-by: Steve Twiss Reviewed-by: Dmitry Osipenko Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman

regulator: core: Log forbidden DRMS operation

2019-02-21T18:53:37Z

When REGULATOR_CHANGE_DRMS is not set, drms_uA_update is a no-op. It used to print a debug message, which was dropped in commit 8a34e979f684 ("regulator: refactor valid_ops_mask checking code") Let's bring the debug message back, because it helps find missing regulator-allow-set-load properties. Signed-off-by: Marc Gonzalez Signed-off-by: Mark Brown

Merge branch 'regulator-5.0' into regulator-5.1 stpmic1 const/range

2019-02-19T11:06:41Z

regulator: core: Drop lockdep annotation in drms_uA_update()

2019-02-19T11:01:44Z

commit e5e21f70bfd3 ("regulator: core: Take lock before applying system load") took the regulator lock before calling drms_uA_update() in order to silence a lockdep warning during regulator_register(). However, we are not supposed to need locks at this point as the regulator is in the process of being registered, so there should be no possibility of concurrent access. Instead, remove the unnecessary locking and simply drop the lockdep annotation, since it is no longer valid. Fixes: e5e21f70bfd3 ("regulator: core: Take lock before applying system load") Signed-off-by: Niklas Cassel Signed-off-by: Mark Brown

regulator: core: remove unused rdev_get_supply()

2019-02-18T17:14:49Z

This is a remnant of commit 70a7fb80e85a ("regulator: core: Fix nested locking of supplies"). Signed-off-by: Masahiro Yamada Signed-off-by: Mark Brown

regulator: core: Take lock before applying system load

2019-02-15T17:45:11Z

Take the regulator lock before applying system load. Fixes the following lockdep splat: [ 5.583581] WARNING: CPU: 1 PID: 16 at drivers/regulator/core.c:925 drms_uA_update+0x114/0x360 [ 5.588467] Modules linked in: [ 5.596833] CPU: 1 PID: 16 Comm: kworker/1:0 Not tainted 5.0.0-rc6-next-20190213-00002-g0fce66ab480f #18 [ 5.599933] Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) [ 5.609544] Workqueue: events qcom_channel_state_worker [ 5.616209] pstate: 60000005 (nZCv daif -PAN -UAO) [ 5.621152] pc : drms_uA_update+0x114/0x360 [ 5.626006] lr : drms_uA_update+0x110/0x360 [ 5.630084] sp : ffff0000124b3490 [ 5.634242] x29: ffff0000124b3490 x28: ffff800005326e00 [ 5.637735] x27: ffff0000124b35f8 x26: 000000000032bc48 [ 5.643117] x25: ffff800004c7e800 x24: ffff800004c6d500 [ 5.648411] x23: ffff800004c38a80 x22: 00000000000000d1 [ 5.653706] x21: 00000000001ab3f0 x20: ffff800004c7e800 [ 5.659001] x19: ffff0000114c3000 x18: ffffffffffffffff [ 5.664297] x17: 0000000000000000 x16: 0000000000000000 [ 5.669592] x15: ffff0000114c3808 x14: 0720072007200720 [ 5.674888] x13: 00000000199c9b28 x12: ffff80002bcccc40 [ 5.680183] x11: ffff000012286000 x10: ffff0000114c3808 [ 5.685477] x9 : 0720072007200720 x8 : ffff000010e9e808 [ 5.690772] x7 : ffff0000106da568 x6 : 0000000000000000 [ 5.696067] x5 : 0000000000000000 x4 : 0000000000000000 [ 5.701362] x3 : 0000000000000004 x2 : 0000000000000000 [ 5.706658] x1 : 0000000000000000 x0 : 0000000000000000 [ 5.711952] Call trace: [ 5.717223] drms_uA_update+0x114/0x360 [ 5.719405] regulator_register+0xb30/0x1140 [ 5.723230] devm_regulator_register+0x4c/0xa8 [ 5.727745] rpm_reg_probe+0xfc/0x1b0 [ 5.731992] platform_drv_probe+0x50/0xa0 [ 5.735727] really_probe+0x20c/0x2b8 [ 5.739718] driver_probe_device+0x58/0x100 [ 5.743368] __device_attach_driver+0x90/0xd0 [ 5.747363] bus_for_each_drv+0x64/0xc8 [ 5.751870] __device_attach+0xd8/0x138 [ 5.755516] device_initial_probe+0x10/0x18 [ 5.759341] bus_probe_device+0x98/0xa0 [ 5.763502] device_add+0x3d0/0x640 [ 5.767319] of_device_add+0x48/0x58 [ 5.770793] of_platform_device_create_pdata+0xb0/0x128 [ 5.774629] of_platform_bus_create+0x174/0x370 [ 5.779569] of_platform_populate+0x78/0xe0 [ 5.784082] qcom_smd_rpm_probe+0x80/0xa0 [ 5.788245] rpmsg_dev_probe+0x114/0x1a0 [ 5.792411] really_probe+0x20c/0x2b8 [ 5.796401] driver_probe_device+0x58/0x100 [ 5.799964] __device_attach_driver+0x90/0xd0 [ 5.803960] bus_for_each_drv+0x64/0xc8 [ 5.808468] __device_attach+0xd8/0x138 [ 5.812115] device_initial_probe+0x10/0x18 [ 5.815936] bus_probe_device+0x98/0xa0 [ 5.820099] device_add+0x3d0/0x640 [ 5.823916] device_register+0x1c/0x28 [ 5.827391] rpmsg_register_device+0x4c/0x90 [ 5.831216] qcom_channel_state_worker+0x170/0x298 [ 5.835651] process_one_work+0x294/0x6e8 [ 5.840241] worker_thread+0x40/0x450 [ 5.844318] kthread+0x11c/0x120 [ 5.847961] ret_from_fork+0x10/0x18 [ 5.851260] irq event stamp: 9090 [ 5.854820] hardirqs last enabled at (9089): [] console_unlock+0x3e0/0x5b0 [ 5.858086] hardirqs last disabled at (9090): [] do_debug_exception+0x104/0x140 [ 5.866596] softirqs last enabled at (9086): [] __do_softirq+0x474/0x574 [ 5.875446] softirqs last disabled at (9079): [] irq_exit+0x13c/0x148 [ 5.883598] ---[ end trace 6984ef7f081afa21 ]--- Fixes: fa94e48e13a1 ("regulator: core: Apply system load even if no consumer loads") Signed-off-by: Niklas Cassel Signed-off-by: Mark Brown

regulator: fix device unlinking

2019-02-08T13:05:14Z

Device links are refcounted, device_link_remove() has to be called as many times as device_link_add(). Signed-off-by: Guennadi Liakhovetski Signed-off-by: Mark Brown

regulator: core: Only support passing enable GPIO descriptors

2019-02-06T16:01:31Z

Now that we changed all providers to pass descriptors into the core for enable GPIOs instead of a global GPIO number, delete the support for passing GPIO numbers in, and we get a cleanup and size reduction in the core, and from a GPIO point of view we use the modern, cleaner interface. Tested-by: Marek Szyprowski Signed-off-by: Linus Walleij Signed-off-by: Mark Brown