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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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21e39809fd
vctrl_enable() and vctrl_disable() call regulator_enable() and regulator_disable(), respectively. However, vctrl_* are regulator ops and should not be calling the locked regulator APIs. Doing so results in a lockdep warning. Instead of exporting more internal regulator ops, model the ctrl supply as an actual supply to vctrl-regulator. At probe time this driver still needs to use the consumer API to fetch its constraints, but otherwise lets the regulator core handle the upstream supply for it. The enable/disable/is_enabled ops are not removed, but now only track state internally. This preserves the original behavior with the ops being available, but one could argue that the original behavior was already incorrect: the internal state would not match the upstream supply if that supply had another consumer that enabled the supply, while vctrl-regulator was not enabled. The lockdep warning is as follows: WARNING: possible circular locking dependency detected 5.14.0-rc6 #2 Not tainted ------------------------------------------------------ swapper/0/1 is trying to acquire lock: ffffffc011306d00 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent (arch/arm64/include/asm/current.h:19 include/linux/ww_mutex.h:111 drivers/regulator/core.c:329) but task is already holding lock: ffffff8004a77160 (regulator_ww_class_mutex){+.+.}-{3:3}, at: regulator_lock_recursive (drivers/regulator/core.c:156 drivers/regulator/core.c:263) which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (regulator_ww_class_mutex){+.+.}-{3:3}: __mutex_lock_common (include/asm-generic/atomic-instrumented.h:606 include/asm-generic/atomic-long.h:29 kernel/locking/mutex.c:103 kernel/locking/mutex.c:144 kernel/locking/mutex.c:963) ww_mutex_lock (kernel/locking/mutex.c:1199) regulator_lock_recursive (drivers/regulator/core.c:156 drivers/regulator/core.c:263) regulator_lock_dependent (drivers/regulator/core.c:343) regulator_enable (drivers/regulator/core.c:2808) set_machine_constraints (drivers/regulator/core.c:1536) regulator_register (drivers/regulator/core.c:5486) devm_regulator_register (drivers/regulator/devres.c:196) reg_fixed_voltage_probe (drivers/regulator/fixed.c:289) platform_probe (drivers/base/platform.c:1427) [...] -> #1 (regulator_ww_class_acquire){+.+.}-{0:0}: regulator_lock_dependent (include/linux/ww_mutex.h:129 drivers/regulator/core.c:329) regulator_enable (drivers/regulator/core.c:2808) set_machine_constraints (drivers/regulator/core.c:1536) regulator_register (drivers/regulator/core.c:5486) devm_regulator_register (drivers/regulator/devres.c:196) reg_fixed_voltage_probe (drivers/regulator/fixed.c:289) [...] -> #0 (regulator_list_mutex){+.+.}-{3:3}: __lock_acquire (kernel/locking/lockdep.c:3052 (discriminator 4) kernel/locking/lockdep.c:3174 (discriminator 4) kernel/locking/lockdep.c:3789 (discriminator 4) kernel/locking/lockdep.c:5015 (discriminator 4)) lock_acquire (arch/arm64/include/asm/percpu.h:39 kernel/locking/lockdep.c:438 kernel/locking/lockdep.c:5627) __mutex_lock_common (include/asm-generic/atomic-instrumented.h:606 include/asm-generic/atomic-long.h:29 kernel/locking/mutex.c:103 kernel/locking/mutex.c:144 kernel/locking/mutex.c:963) mutex_lock_nested (kernel/locking/mutex.c:1125) regulator_lock_dependent (arch/arm64/include/asm/current.h:19 include/linux/ww_mutex.h:111 drivers/regulator/core.c:329) regulator_enable (drivers/regulator/core.c:2808) vctrl_enable (drivers/regulator/vctrl-regulator.c:400) _regulator_do_enable (drivers/regulator/core.c:2617) _regulator_enable (drivers/regulator/core.c:2764) regulator_enable (drivers/regulator/core.c:308 drivers/regulator/core.c:2809) _set_opp (drivers/opp/core.c:819 drivers/opp/core.c:1072) dev_pm_opp_set_rate (drivers/opp/core.c:1164) set_target (drivers/cpufreq/cpufreq-dt.c:62) __cpufreq_driver_target (drivers/cpufreq/cpufreq.c:2216 drivers/cpufreq/cpufreq.c:2271) cpufreq_online (drivers/cpufreq/cpufreq.c:1488 (discriminator 2)) cpufreq_add_dev (drivers/cpufreq/cpufreq.c:1563) subsys_interface_register (drivers/base/bus.c:?) cpufreq_register_driver (drivers/cpufreq/cpufreq.c:2819) dt_cpufreq_probe (drivers/cpufreq/cpufreq-dt.c:344) [...] other info that might help us debug this: Chain exists of: regulator_list_mutex --> regulator_ww_class_acquire --> regulator_ww_class_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(regulator_ww_class_mutex); lock(regulator_ww_class_acquire); lock(regulator_ww_class_mutex); lock(regulator_list_mutex); *** DEADLOCK *** 6 locks held by swapper/0/1: #0: ffffff8002d32188 (&dev->mutex){....}-{3:3}, at: __device_driver_lock (drivers/base/dd.c:1030) #1: ffffffc0111a0520 (cpu_hotplug_lock){++++}-{0:0}, at: cpufreq_register_driver (drivers/cpufreq/cpufreq.c:2792 (discriminator 2)) #2: ffffff8002a8d918 (subsys mutex#9){+.+.}-{3:3}, at: subsys_interface_register (drivers/base/bus.c:1033) #3: ffffff800341bb90 (&policy->rwsem){+.+.}-{3:3}, at: cpufreq_online (include/linux/bitmap.h:285 include/linux/cpumask.h:405 drivers/cpufreq/cpufreq.c:1399) #4: ffffffc011f0b7b8 (regulator_ww_class_acquire){+.+.}-{0:0}, at: regulator_enable (drivers/regulator/core.c:2808) #5: ffffff8004a77160 (regulator_ww_class_mutex){+.+.}-{3:3}, at: regulator_lock_recursive (drivers/regulator/core.c:156 drivers/regulator/core.c:263) stack backtrace: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.14.0-rc6 #2 7c8f8996d021ed0f65271e6aeebf7999de74a9fa Hardware name: Google Scarlet (DT) Call trace: dump_backtrace (arch/arm64/kernel/stacktrace.c:161) show_stack (arch/arm64/kernel/stacktrace.c:218) dump_stack_lvl (lib/dump_stack.c:106 (discriminator 2)) dump_stack (lib/dump_stack.c:113) print_circular_bug (kernel/locking/lockdep.c:?) check_noncircular (kernel/locking/lockdep.c:?) __lock_acquire (kernel/locking/lockdep.c:3052 (discriminator 4) kernel/locking/lockdep.c:3174 (discriminator 4) kernel/locking/lockdep.c:3789 (discriminator 4) kernel/locking/lockdep.c:5015 (discriminator 4)) lock_acquire (arch/arm64/include/asm/percpu.h:39 kernel/locking/lockdep.c:438 kernel/locking/lockdep.c:5627) __mutex_lock_common (include/asm-generic/atomic-instrumented.h:606 include/asm-generic/atomic-long.h:29 kernel/locking/mutex.c:103 kernel/locking/mutex.c:144 kernel/locking/mutex.c:963) mutex_lock_nested (kernel/locking/mutex.c:1125) regulator_lock_dependent (arch/arm64/include/asm/current.h:19 include/linux/ww_mutex.h:111 drivers/regulator/core.c:329) regulator_enable (drivers/regulator/core.c:2808) vctrl_enable (drivers/regulator/vctrl-regulator.c:400) _regulator_do_enable (drivers/regulator/core.c:2617) _regulator_enable (drivers/regulator/core.c:2764) regulator_enable (drivers/regulator/core.c:308 drivers/regulator/core.c:2809) _set_opp (drivers/opp/core.c:819 drivers/opp/core.c:1072) dev_pm_opp_set_rate (drivers/opp/core.c:1164) set_target (drivers/cpufreq/cpufreq-dt.c:62) __cpufreq_driver_target (drivers/cpufreq/cpufreq.c:2216 drivers/cpufreq/cpufreq.c:2271) cpufreq_online (drivers/cpufreq/cpufreq.c:1488 (discriminator 2)) cpufreq_add_dev (drivers/cpufreq/cpufreq.c:1563) subsys_interface_register (drivers/base/bus.c:?) cpufreq_register_driver (drivers/cpufreq/cpufreq.c:2819) dt_cpufreq_probe (drivers/cpufreq/cpufreq-dt.c:344) [...] Reported-by: Brian Norris <briannorris@chromium.org> Fixes: |
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| .. | ||
| 88pg86x.c | ||
| 88pm800-regulator.c | ||
| 88pm8607.c | ||
| aat2870-regulator.c | ||
| ab8500-ext.c | ||
| ab8500.c | ||
| act8865-regulator.c | ||
| act8945a-regulator.c | ||
| ad5398.c | ||
| anatop-regulator.c | ||
| arizona-ldo1.c | ||
| arizona-micsupp.c | ||
| as3711-regulator.c | ||
| as3722-regulator.c | ||
| atc260x-regulator.c | ||
| axp20x-regulator.c | ||
| bcm590xx-regulator.c | ||
| bd718x7-regulator.c | ||
| bd9571mwv-regulator.c | ||
| bd9576-regulator.c | ||
| bd71815-regulator.c | ||
| bd71828-regulator.c | ||
| core.c | ||
| cpcap-regulator.c | ||
| cros-ec-regulator.c | ||
| da903x-regulator.c | ||
| da9052-regulator.c | ||
| da9055-regulator.c | ||
| da9062-regulator.c | ||
| da9063-regulator.c | ||
| da9121-regulator.c | ||
| da9121-regulator.h | ||
| da9210-regulator.c | ||
| da9210-regulator.h | ||
| da9211-regulator.c | ||
| da9211-regulator.h | ||
| db8500-prcmu.c | ||
| dbx500-prcmu.c | ||
| dbx500-prcmu.h | ||
| devres.c | ||
| dummy.c | ||
| dummy.h | ||
| fan53555.c | ||
| fan53880.c | ||
| fixed-helper.c | ||
| fixed.c | ||
| gpio-regulator.c | ||
| helpers.c | ||
| hi655x-regulator.c | ||
| hi6421-regulator.c | ||
| hi6421v530-regulator.c | ||
| hi6421v600-regulator.c | ||
| internal.h | ||
| irq_helpers.c | ||
| isl6271a-regulator.c | ||
| isl9305.c | ||
| Kconfig | ||
| lm363x-regulator.c | ||
| lochnagar-regulator.c | ||
| lp872x.c | ||
| lp873x-regulator.c | ||
| lp3971.c | ||
| lp3972.c | ||
| lp8755.c | ||
| lp8788-buck.c | ||
| lp8788-ldo.c | ||
| lp87565-regulator.c | ||
| ltc3589.c | ||
| ltc3676.c | ||
| Makefile | ||
| max1586.c | ||
| max8649.c | ||
| max8660.c | ||
| max8893.c | ||
| max8907-regulator.c | ||
| max8925-regulator.c | ||
| max8952.c | ||
| max8973-regulator.c | ||
| max8997-regulator.c | ||
| max8998.c | ||
| max14577-regulator.c | ||
| max77620-regulator.c | ||
| max77650-regulator.c | ||
| max77686-regulator.c | ||
| max77693-regulator.c | ||
| max77802-regulator.c | ||
| max77826-regulator.c | ||
| mc13xxx-regulator-core.c | ||
| mc13xxx.h | ||
| mc13783-regulator.c | ||
| mc13892-regulator.c | ||
| mcp16502.c | ||
| mp886x.c | ||
| mp5416.c | ||
| mp8859.c | ||
| mpq7920.c | ||
| mpq7920.h | ||
| mt6311-regulator.c | ||
| mt6311-regulator.h | ||
| mt6315-regulator.c | ||
| mt6323-regulator.c | ||
| mt6358-regulator.c | ||
| mt6359-regulator.c | ||
| mt6360-regulator.c | ||
| mt6380-regulator.c | ||
| mt6397-regulator.c | ||
| mtk-dvfsrc-regulator.c | ||
| of_regulator.c | ||
| palmas-regulator.c | ||
| pbias-regulator.c | ||
| pca9450-regulator.c | ||
| pcap-regulator.c | ||
| pcf50633-regulator.c | ||
| pf8x00-regulator.c | ||
| pfuze100-regulator.c | ||
| pv88060-regulator.c | ||
| pv88060-regulator.h | ||
| pv88080-regulator.c | ||
| pv88080-regulator.h | ||
| pv88090-regulator.c | ||
| pv88090-regulator.h | ||
| pwm-regulator.c | ||
| qcom-labibb-regulator.c | ||
| qcom-rpmh-regulator.c | ||
| qcom_rpm-regulator.c | ||
| qcom_smd-regulator.c | ||
| qcom_spmi-regulator.c | ||
| qcom_usb_vbus-regulator.c | ||
| rc5t583-regulator.c | ||
| rk808-regulator.c | ||
| rn5t618-regulator.c | ||
| rohm-regulator.c | ||
| rpi-panel-attiny-regulator.c | ||
| rt4801-regulator.c | ||
| rt4831-regulator.c | ||
| rt5033-regulator.c | ||
| rt6160-regulator.c | ||
| rt6245-regulator.c | ||
| rtmv20-regulator.c | ||
| rtq2134-regulator.c | ||
| rtq6752-regulator.c | ||
| s2mpa01.c | ||
| s2mps11.c | ||
| s5m8767.c | ||
| sc2731-regulator.c | ||
| scmi-regulator.c | ||
| sky81452-regulator.c | ||
| slg51000-regulator.c | ||
| slg51000-regulator.h | ||
| stm32-booster.c | ||
| stm32-pwr.c | ||
| stm32-vrefbuf.c | ||
| stpmic1_regulator.c | ||
| stw481x-vmmc.c | ||
| sy7636a-regulator.c | ||
| sy8106a-regulator.c | ||
| sy8824x.c | ||
| sy8827n.c | ||
| ti-abb-regulator.c | ||
| tps6105x-regulator.c | ||
| tps6507x-regulator.c | ||
| tps6524x-regulator.c | ||
| tps6586x-regulator.c | ||
| tps51632-regulator.c | ||
| tps62360-regulator.c | ||
| tps65023-regulator.c | ||
| tps65086-regulator.c | ||
| tps65090-regulator.c | ||
| tps65132-regulator.c | ||
| tps65217-regulator.c | ||
| tps65218-regulator.c | ||
| tps65910-regulator.c | ||
| tps65912-regulator.c | ||
| tps80031-regulator.c | ||
| twl-regulator.c | ||
| twl6030-regulator.c | ||
| uniphier-regulator.c | ||
| userspace-consumer.c | ||
| vctrl-regulator.c | ||
| vexpress-regulator.c | ||
| virtual.c | ||
| vqmmc-ipq4019-regulator.c | ||
| wm831x-dcdc.c | ||
| wm831x-isink.c | ||
| wm831x-ldo.c | ||
| wm8350-regulator.c | ||
| wm8400-regulator.c | ||
| wm8994-regulator.c | ||