Hi Mark, On 18.01.2021 21:49, Mark Brown wrote: > On Tue, Jan 12, 2021 at 10:34:19PM +0100, Marek Szyprowski wrote: >> ====================================================== >> WARNING: possible circular locking dependency detected >> 5.11.0-rc1-00008-geaa7995c529b #10095 Not tainted >> ------------------------------------------------------ >> swapper/0/1 is trying to acquire lock: >> c12e1b80 (regulator_list_mutex){+.+.}-{3:3}, at: >> regulator_lock_dependent+0x4c/0x2b0 > If you're sending backtraces or other enormous reports like this please > run them through addr2line first so that things are a bit more leigible. Well, I had a little time to process that issue, so I just copy-pasted the kernel log with the hope it will be useful. The trace is really long, but the function call stack is imho readable. If you need more details about any specific trace, just ask. I don't know any good method of processing the raw kernel logs with addr2line and keeping things readable. >> but task is already holding lock: >> df7190c0 (regulator_ww_class_mutex){+.+.}-{3:3}, at: >> regulator_resolve_supply+0x44/0x318 >> >> which lock already depends on the new lock. > Does this help (completely untested): Sadly nope. I get same warning: ====================================================== WARNING: possible circular locking dependency detected 5.11.0-rc3-next-20210118-00005-g56a65ff7ca8b #10162 Not tainted ------------------------------------------------------ swapper/0/1 is trying to acquire lock: c12e1e40 (regulator_list_mutex){+.+.}-{3:3}, at: regulator_lock_dependent+0x4c/0x2b4 but task is already holding lock: df4fe8c0 (regulator_ww_class_mutex){+.+.}-{3:3}, at: regulator_resolve_supply+0x98/0x320 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (regulator_ww_class_mutex){+.+.}-{3:3}: ww_mutex_lock+0x48/0x88 regulator_lock_recursive+0x84/0x1f4 regulator_lock_dependent+0x188/0x2b4 regulator_enable+0x30/0xe4 dwc3_exynos_probe+0x17c/0x2c0 platform_probe+0x80/0xc0 really_probe+0x1d4/0x4ec driver_probe_device+0x78/0x1d8 device_driver_attach+0x58/0x60 __driver_attach+0xfc/0x160 bus_for_each_dev+0x6c/0xb8 bus_add_driver+0x170/0x20c driver_register+0x78/0x10c do_one_initcall+0x88/0x438 kernel_init_freeable+0x190/0x1e0 kernel_init+0x8/0x118 ret_from_fork+0x14/0x38 0x0 -> #1 (regulator_ww_class_acquire){+.+.}-{0:0}: regulator_enable+0x30/0xe4 dwc3_exynos_probe+0x17c/0x2c0 platform_probe+0x80/0xc0 really_probe+0x1d4/0x4ec driver_probe_device+0x78/0x1d8 device_driver_attach+0x58/0x60 __driver_attach+0xfc/0x160 bus_for_each_dev+0x6c/0xb8 bus_add_driver+0x170/0x20c driver_register+0x78/0x10c do_one_initcall+0x88/0x438 kernel_init_freeable+0x190/0x1e0 kernel_init+0x8/0x118 ret_from_fork+0x14/0x38 0x0 -> #0 (regulator_list_mutex){+.+.}-{3:3}: lock_acquire+0x314/0x5d0 __mutex_lock+0xa4/0xb60 mutex_lock_nested+0x1c/0x24 regulator_lock_dependent+0x4c/0x2b4 regulator_enable+0x30/0xe4 regulator_resolve_supply+0x1d0/0x320 regulator_register_resolve_supply+0x14/0x78 class_for_each_device+0x68/0xe8 regulator_register+0xa30/0xca0 devm_regulator_register+0x40/0x70 tps65090_regulator_probe+0x150/0x648 platform_probe+0x80/0xc0 really_probe+0x1d4/0x4ec driver_probe_device+0x78/0x1d8 bus_for_each_drv+0x78/0xbc __device_attach+0xe8/0x180 bus_probe_device+0x88/0x90 device_add+0x4c8/0x7ec platform_device_add+0x120/0x25c mfd_add_devices+0x580/0x60c tps65090_i2c_probe+0xb8/0x184 i2c_device_probe+0x234/0x2a4 really_probe+0x1d4/0x4ec driver_probe_device+0x78/0x1d8 bus_for_each_drv+0x78/0xbc __device_attach+0xe8/0x180 bus_probe_device+0x88/0x90 device_add+0x4c8/0x7ec i2c_new_client_device+0x15c/0x27c of_i2c_register_devices+0x114/0x184 i2c_register_adapter+0x1d8/0x6dc ec_i2c_probe+0xc8/0x124 platform_probe+0x80/0xc0 really_probe+0x1d4/0x4ec driver_probe_device+0x78/0x1d8 bus_for_each_drv+0x78/0xbc __device_attach+0xe8/0x180 bus_probe_device+0x88/0x90 device_add+0x4c8/0x7ec of_platform_device_create_pdata+0x90/0xc8 of_platform_bus_create+0x1a0/0x4ec of_platform_populate+0x88/0x120 devm_of_platform_populate+0x40/0x80 cros_ec_register+0x174/0x308 cros_ec_spi_probe+0x16c/0x1ec spi_probe+0x88/0xac really_probe+0x1d4/0x4ec driver_probe_device+0x78/0x1d8 device_driver_attach+0x58/0x60 __driver_attach+0xfc/0x160 bus_for_each_dev+0x6c/0xb8 bus_add_driver+0x170/0x20c driver_register+0x78/0x10c do_one_initcall+0x88/0x438 kernel_init_freeable+0x190/0x1e0 kernel_init+0x8/0x118 ret_from_fork+0x14/0x38 0x0 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 *** 5 locks held by swapper/0/1: #0: dfbef0c8 (&dev->mutex){....}-{3:3}, at: device_driver_attach+0x18/0x60 #1: df4f84d8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x34/0x180 #2: df4f98e8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x34/0x180 #3: df509cd8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x34/0x180 #4: df4fe8c0 (regulator_ww_class_mutex){+.+.}-{3:3}, at: regulator_resolve_supply+0x98/0x320 stack backtrace: CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.11.0-rc3-next-20210118-00005-g56a65ff7ca8b #10162 Hardware name: Samsung Exynos (Flattened Device Tree) [<c01116e8>] (unwind_backtrace) from [<c010cf58>] (show_stack+0x10/0x14) [<c010cf58>] (show_stack) from [<c0b443c0>] (dump_stack+0xa4/0xc4) [<c0b443c0>] (dump_stack) from [<c01932e0>] (check_noncircular+0x14c/0x164) [<c01932e0>] (check_noncircular) from [<c0196a08>] (__lock_acquire+0x181c/0x3204) [<c0196a08>] (__lock_acquire) from [<c01990cc>] (lock_acquire+0x314/0x5d0) [<c01990cc>] (lock_acquire) from [<c0b4bd54>] (__mutex_lock+0xa4/0xb60) [<c0b4bd54>] (__mutex_lock) from [<c0b4c82c>] (mutex_lock_nested+0x1c/0x24) [<c0b4c82c>] (mutex_lock_nested) from [<c05d4544>] (regulator_lock_dependent+0x4c/0x2b4) [<c05d4544>] (regulator_lock_dependent) from [<c05d99c0>] (regulator_enable+0x30/0xe4) [<c05d99c0>] (regulator_enable) from [<c05d9c44>] (regulator_resolve_supply+0x1d0/0x320) [<c05d9c44>] (regulator_resolve_supply) from [<c05da130>] (regulator_register_resolve_supply+0x14/0x78) [<c05da130>] (regulator_register_resolve_supply) from [<c06aba80>] (class_for_each_device+0x68/0xe8) [<c06aba80>] (class_for_each_device) from [<c05db5e0>] (regulator_register+0xa30/0xca0) [<c05db5e0>] (regulator_register) from [<c05dd430>] (devm_regulator_register+0x40/0x70) [<c05dd430>] (devm_regulator_register) from [<c05e6218>] (tps65090_regulator_probe+0x150/0x648) [<c05e6218>] (tps65090_regulator_probe) from [<c06aca70>] (platform_probe+0x80/0xc0) [<c06aca70>] (platform_probe) from [<c06a9b9c>] (really_probe+0x1d4/0x4ec) [<c06a9b9c>] (really_probe) from [<c06a9f2c>] (driver_probe_device+0x78/0x1d8) [<c06a9f2c>] (driver_probe_device) from [<c06a7c24>] (bus_for_each_drv+0x78/0xbc) [<c06a7c24>] (bus_for_each_drv) from [<c06a9928>] (__device_attach+0xe8/0x180) [<c06a9928>] (__device_attach) from [<c06a89d0>] (bus_probe_device+0x88/0x90) [<c06a89d0>] (bus_probe_device) from [<c06a662c>] (device_add+0x4c8/0x7ec) [<c06a662c>] (device_add) from [<c06ac634>] (platform_device_add+0x120/0x25c) [<c06ac634>] (platform_device_add) from [<c06de87c>] (mfd_add_devices+0x580/0x60c) [<c06de87c>] (mfd_add_devices) from [<c06e0ce8>] (tps65090_i2c_probe+0xb8/0x184) [<c06e0ce8>] (tps65090_i2c_probe) from [<c082d2b8>] (i2c_device_probe+0x234/0x2a4) [<c082d2b8>] (i2c_device_probe) from [<c06a9b9c>] (really_probe+0x1d4/0x4ec) [<c06a9b9c>] (really_probe) from [<c06a9f2c>] (driver_probe_device+0x78/0x1d8) [<c06a9f2c>] (driver_probe_device) from [<c06a7c24>] (bus_for_each_drv+0x78/0xbc) [<c06a7c24>] (bus_for_each_drv) from [<c06a9928>] (__device_attach+0xe8/0x180) [<c06a9928>] (__device_attach) from [<c06a89d0>] (bus_probe_device+0x88/0x90) [<c06a89d0>] (bus_probe_device) from [<c06a662c>] (device_add+0x4c8/0x7ec) [<c06a662c>] (device_add) from [<c082f884>] (i2c_new_client_device+0x15c/0x27c) [<c082f884>] (i2c_new_client_device) from [<c08332dc>] (of_i2c_register_devices+0x114/0x184) [<c08332dc>] (of_i2c_register_devices) from [<c0830250>] (i2c_register_adapter+0x1d8/0x6dc) [<c0830250>] (i2c_register_adapter) from [<c0838a1c>] (ec_i2c_probe+0xc8/0x124) [<c0838a1c>] (ec_i2c_probe) from [<c06aca70>] (platform_probe+0x80/0xc0) [<c06aca70>] (platform_probe) from [<c06a9b9c>] (really_probe+0x1d4/0x4ec) [<c06a9b9c>] (really_probe) from [<c06a9f2c>] (driver_probe_device+0x78/0x1d8) [<c06a9f2c>] (driver_probe_device) from [<c06a7c24>] (bus_for_each_drv+0x78/0xbc) [<c06a7c24>] (bus_for_each_drv) from [<c06a9928>] (__device_attach+0xe8/0x180) [<c06a9928>] (__device_attach) from [<c06a89d0>] (bus_probe_device+0x88/0x90) [<c06a89d0>] (bus_probe_device) from [<c06a662c>] (device_add+0x4c8/0x7ec) [<c06a662c>] (device_add) from [<c08bba20>] (of_platform_device_create_pdata+0x90/0xc8) [<c08bba20>] (of_platform_device_create_pdata) from [<c08bbc04>] (of_platform_bus_create+0x1a0/0x4ec) [<c08bbc04>] (of_platform_bus_create) from [<c08bc104>] (of_platform_populate+0x88/0x120) [<c08bc104>] (of_platform_populate) from [<c08bc1f0>] (devm_of_platform_populate+0x40/0x80) [<c08bc1f0>] (devm_of_platform_populate) from [<c08c1910>] (cros_ec_register+0x174/0x308) [<c08c1910>] (cros_ec_register) from [<c08c2ca0>] (cros_ec_spi_probe+0x16c/0x1ec) [<c08c2ca0>] (cros_ec_spi_probe) from [<c07240fc>] (spi_probe+0x88/0xac) [<c07240fc>] (spi_probe) from [<c06a9b9c>] (really_probe+0x1d4/0x4ec) [<c06a9b9c>] (really_probe) from [<c06a9f2c>] (driver_probe_device+0x78/0x1d8) [<c06a9f2c>] (driver_probe_device) from [<c06aa444>] (device_driver_attach+0x58/0x60) [<c06aa444>] (device_driver_attach) from [<c06aa548>] (__driver_attach+0xfc/0x160) [<c06aa548>] (__driver_attach) from [<c06a7b4c>] (bus_for_each_dev+0x6c/0xb8) [<c06a7b4c>] (bus_for_each_dev) from [<c06a8c84>] (bus_add_driver+0x170/0x20c) [<c06a8c84>] (bus_add_driver) from [<c06ab3e8>] (driver_register+0x78/0x10c) [<c06ab3e8>] (driver_register) from [<c0102428>] (do_one_initcall+0x88/0x438) [<c0102428>] (do_one_initcall) from [<c11010d4>] (kernel_init_freeable+0x190/0x1e0) [<c11010d4>] (kernel_init_freeable) from [<c0b47db0>] (kernel_init+0x8/0x118) [<c0b47db0>] (kernel_init) from [<c010011c>] (ret_from_fork+0x14/0x38) Exception stack(0xc1ce3fb0 to 0xc1ce3ff8) Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland