Hello Alexander,
thanks for looking into that!
On Fri, 2023-04-21 at 15:48 +0200, Alexander Stein wrote:
> Unfortuantely this was just hiding another call path from
> lpi2c_imx_xfer to
> clk_bulk_prepare. Here is my kernel log:
Yes, soon after publishing the patch I reproduced your log as well,
that's why I didn't follow up on the original patch, as it indeed
doesn't solve all the LOCKDEP splats with lpi2c involved and I didn't
have time to look into this yet.
> [ 22.264508] ======================================================
> [ 22.270697] WARNING: possible circular locking dependency detected
> [ 22.276893] 6.3.0-rc7-next-20230420+ #6 Not tainted
> [ 22.281782] ------------------------------------------------------
> [ 22.287968] kworker/2:3/93 is trying to acquire lock:
> [ 22.293034] ffff800009d38bf8 (prepare_lock){+.+.}-{3:3}, at:
> clk_prepare_lock+0x48/0x9c
> [ 22.301095]
> [ 22.301095] but task is already holding lock:
> [ 22.306942] ffff0000039ab100 (i2c_register_adapter){+.+.}-{3:3},
> at:
> i2c_adapter_lock_bus+0x20/0x2c
> [ 22.316046]
> [ 22.316046] which lock already depends on the new lock.
> [ 22.316046]
> [ 22.324238]
> [ 22.324238] the existing dependency chain (in reverse order) is:
> [ 22.331727]
> [ 22.331727] -> #2 (i2c_register_adapter){+.+.}-{3:3}:
> [ 22.338295] __lock_acquire+0x370/0x6e8
> [ 22.342674] lock_acquire.part.0+0xcc/0x208
> [ 22.347399] lock_acquire+0x94/0x14c
> [ 22.351509] rt_mutex_lock_nested+0x5c/0x98
> [ 22.356235] i2c_adapter_lock_bus+0x20/0x2c
> [ 22.360961] i2c_transfer+0x80/0x114
> [ 22.365069] regmap_i2c_read+0x5c/0xa0
> [ 22.369362] _regmap_raw_read+0x110/0x2dc
> [ 22.373905] _regmap_bus_read+0x40/0x74
> [ 22.378274] _regmap_read+0x74/0x248
> [ 22.382393] regmap_read+0x48/0x70
> [ 22.386337] pcf85063_probe+0xf0/0x4f4
> [ 22.390640] i2c_device_probe+0x100/0x2d4
> [ 22.395206] call_driver_probe+0x28/0x15c
> [ 22.399750] really_probe+0x180/0x320
> [ 22.403946] __driver_probe_device+0x84/0x144
> [ 22.408837] driver_probe_device+0x38/0x150
> [ 22.413554] __device_attach_driver+0xcc/0x194
> [ 22.418532] bus_for_each_drv+0x80/0xdc
> [ 22.422910] __device_attach+0xa8/0x1f8
> [ 22.426545] systemd-journald[128]: Oldest entry in
> /var/log/journal/
> e4579cc7db6747028247b9b859e132d6/system.joural is older than the
> configured
> file retention duration (1month), suggesting rotation.
> [ 22.427278] device_initial_probe+0x10/0x18
> [ 22.427290] bus_probe_device+0xa4/0xa8
> [ 22.427299] device_add+0x3b0/0x508
> [ 22.427311] device_register+0x1c/0x28
> [ 22.427323] i2c_new_client_device+0x1c8/0x2bc
> [ 22.427333] of_i2c_register_device+0xb4/0xdc
> [ 22.427344] of_i2c_register_devices+0x80/0x154
> [ 22.456329] systemd-journald[128]: /var/log/journal/
> e4579cc7db6747028247b9b859e132d6/system.journal: Journal heaer limits
> reached
> or header out-of-date, rotating.
> [ 22.458176] i2c_register_adapter+0x184/0x4c8
> [ 22.458202] __i2c_add_numbered_adapter+0x5c/0xa4
> [ 22.502097] i2c_add_adapter+0xa0/0xcc
> [ 22.502122] lpi2c_imx_probe+0x23c/0x350
> [ 22.502135] platform_probe+0x64/0xfc
> [ 22.502146] call_driver_probe+0x28/0x15c
> [ 22.502155] really_probe+0x180/0x320
> [ 22.502164] __driver_probe_device+0x84/0x144
> [ 22.502173] driver_probe_device+0x38/0x150
> [ 22.502182] __device_attach_driver+0xcc/0x194
> [ 22.502191] bus_for_each_drv+0x80/0xdc
> [ 22.502204] __device_attach+0xa8/0x1f8
> [ 22.502212] device_initial_probe+0x10/0x18
> [ 22.502222] bus_probe_device+0xa4/0xa8
> [ 22.502230] deferred_probe_work_func+0xa0/0xf0
> [ 22.502239] process_one_work+0x284/0x5b0
> [ 22.502252] worker_thread+0x68/0x39c
> [ 22.502263] kthread+0x104/0x108
> [ 22.502274] ret_from_fork+0x10/0x20
> [ 22.502286]
> [ 22.502286] -> #1 (rtc_pcf85063:594:(&config->regmap)-
> >lock){+.+.}-{3:3}:
> [ 22.502310] __lock_acquire+0x370/0x6e8
> [ 22.502322] lock_acquire.part.0+0xcc/0x208
> [ 22.502332] lock_acquire+0x94/0x14c
> [ 22.502341] __mutex_lock+0x9c/0x838
> [ 22.502353] mutex_lock_nested+0x20/0x28
> [ 22.502364] regmap_lock_mutex+0x10/0x18
> [ 22.502377] regmap_read+0x38/0x70
> [ 22.502389] pcf85063_clkout_recalc_rate+0x2c/0x78
> [ 22.502403] __clk_core_init+0x46c/0x4e0
> [ 22.502417] __clk_register+0x160/0x23c
> [ 22.502429] devm_clk_register+0x58/0xb4
> [ 22.502441] pcf85063_probe+0x238/0x4f4
> [ 22.502451] i2c_device_probe+0x100/0x2d4
> [ 22.502465] call_driver_probe+0x28/0x15c
> [ 22.502473] really_probe+0x180/0x320
> [ 22.502482] __driver_probe_device+0x84/0x144
> [ 22.502491] driver_probe_device+0x38/0x150
> [ 22.502500] __device_attach_driver+0xcc/0x194
> [ 22.502509] bus_for_each_drv+0x80/0xdc
> [ 22.502521] __device_attach+0xa8/0x1f8
> [ 22.502530] device_initial_probe+0x10/0x18
> [ 22.502539] bus_probe_device+0xa4/0xa8
> [ 22.502548] device_add+0x3b0/0x508
> [ 22.502559] device_register+0x1c/0x28
> [ 22.502570] i2c_new_client_device+0x1c8/0x2bc
> [ 22.502580] of_i2c_register_device+0xb4/0xdc
> [ OK ] Started Network Time Synchronization[ 22.502589]
> of_i2c_register_devices+0x80/0x154
> .[ 22.502599] i2c_register_adapter+0x184/0x4c8
>
> [ 22.502607] __i2c_add_numbered_adapter+0x5c/0xa4
> [ 22.502616] i2c_add_adapter+0xa0/0xcc
> [ 22.502624] lpi2c_imx_probe+0x23c/0x350
> [ 22.502636] platform_probe+0x64/0xfc
> [ 22.502646] call_driver_probe+0x28/0x15c
> [ 22.502655] really_probe+0x180/0x320
> [ 22.502663] __driver_probe_device+0x84/0x144
> [ 22.502672] driver_probe_device+0x38/0x150
> [ 22.502681] __device_attach_driver+0xcc/0x194
> [ 22.502690] bus_for_each_drv+0x80/0xdc
> [ 22.502702] __device_attach+0xa8/0x1f8
> [ 22.502711] device_initial_probe+0x10/0x18
> [ 22.502720] bus_probe_device+0xa4/0xa8
> [ 22.502729] deferred_probe_work_func+0xa0/0xf0
> [ 22.502738] process_one_work+0x284/0x5b0
> [ 22.502749] worker_thread+0x68/0x39c
> [ 22.502760] kthread+0x104/0x108
> [ 22.502770] ret_from_fork+0x10/0x20
> [ 22.502779]
> [ 22.502779] -> #0 (prepare_lock){+.+.}-{3:3}:
> [ 22.502799] check_prev_add+0xb0/0xc80
> [ 22.502809] validate_chain+0x444/0x510
> [ 22.502818] __lock_acquire+0x370/0x6e8
> [ 22.502827] lock_acquire.part.0+0xcc/0x208
> [ 22.502837] lock_acquire+0x94/0x14c
> [ 22.502846] __mutex_lock+0x9c/0x838
> [ 22.502857] mutex_lock_nested+0x20/0x28
> [ 22.502867] clk_prepare_lock+0x48/0x9c
> [ 22.502878] clk_prepare+0x1c/0x3c
> [ 22.502890] clk_bulk_prepare+0x48/0xcc
> [ 22.502899] lpi2c_runtime_resume+0x30/0x84
> [ 22.502910] pm_generic_runtime_resume+0x28/0x3c
> [ 22.502923] __genpd_runtime_resume+0x2c/0xa0
> [ 22.502935] genpd_runtime_resume+0xbc/0x308
> [ 22.502944] __rpm_callback+0x44/0x19c
> [ 22.502953] rpm_callback+0x64/0x70
> [ 22.502962] rpm_resume+0x438/0x6d8
> [ 22.502970] __pm_runtime_resume+0x54/0xb0
> [ 22.502978] lpi2c_imx_master_enable+0x24/0x128
> [ 22.502989] lpi2c_imx_xfer+0x2c/0x3c8
> [ 22.502999] __i2c_transfer+0xe4/0x5a0
> [ 22.503008] i2c_transfer+0x90/0x114
> [ 22.503016] i2c_transfer_buffer_flags+0x58/0x84
> [ 22.503025] regmap_i2c_write+0x1c/0x4c
> [ 22.503035] _regmap_raw_write_impl+0x7dc/0x944
> [ 22.503044] _regmap_bus_raw_write+0x5c/0x74
> [ 22.503052] _regmap_write+0x64/0x238
> [ 22.503060] _regmap_update_bits+0x100/0x11c
> [ 22.503069] regmap_update_bits_base+0x60/0x90
> [ 22.503077] pca953x_gpio_set_value+0x74/0x90
> [ 22.503088] gpiod_set_raw_value_commit+0x6c/0x7c
> [ 22.503098] gpiod_set_value_nocheck+0x68/0x70
> [ 22.503107] gpiod_set_value_cansleep+0x3c/0xa8
> [ 22.503116] gpio_led_set_blocking+0x54/0x7c
> [ 22.503128] set_brightness_delayed+0x90/0xd8
> [ 22.503138] process_one_work+0x284/0x5b0
> [ 22.503149] worker_thread+0x68/0x39c
> [ 22.503160] kthread+0x104/0x108
> [ 22.503169] ret_from_fork+0x10/0x20
> [ 22.503179]
> [ 22.503179] other info that might help us debug this:
> [ 22.503179]
> [ 22.503183] Chain exists of:
> [ 22.503183] prepare_lock --> rtc_pcf85063:594:(&config->regmap)-
> >lock -->
> i2c_register_adapter
> [ 22.503183]
> [ 22.503207] Possible unsafe locking scenario:
> [ 22.503207]
> [ 22.503210] CPU0 CPU1
> [ 22.503213] ---- ----
> [ 22.503216] lock(i2c_register_adapter);
> [ 22.503225]
> lock(rtc_pcf85063:594:(&config-
> > regmap)->lock);
> [ 22.503235]
> lock(i2c_register_adapter);
> [ 22.503244] lock(prepare_lock);
> [ 22.503253]
> [ 22.503253] *** DEADLOCK ***
>
> Now lpi2c_runtime_resume will call into clk_prepare() which also
> calls
> clk_prepare_lock() (identical to clk_get_rate).
--
Alexander Sverdlin
Siemens AG
www.siemens.com
