On 02/07/2020 15:53, Andrzej Pietrasiewicz wrote: > Hi Daniel, > > <snip> > >>>>>> >>>>>> I did reproduce: >>>>>> >>>>>> v5.8-rc3 + series => imx6 hang at boot time >>>>>> v5.8-rc3 => imx6 boots correctly >> >> So finally I succeeded to reproduce it on my imx7 locally. The sensor >> was failing to initialize for another reason related to the legacy >> cooling device, this is why it is not appearing on the imx7. >> >> I can now git-bisect :) >> > > That would be very kind of you, thank you! With the lock correctness option enabled: [ 4.179223] imx_thermal tempmon: Extended Commercial CPU temperature grade - max:105C critical:100C passive:95C [ 4.189557] [ 4.191060] ============================================ [ 4.196378] WARNING: possible recursive locking detected [ 4.201699] 5.8.0-rc3-00011-gf5e50bf4d3ef #42 Not tainted [ 4.207102] -------------------------------------------- [ 4.212421] kworker/0:3/54 is trying to acquire lock: [ 4.217480] ca09a3e4 (&tz->lock){+.+.}-{3:3}, at: thermal_zone_device_is_enabled+0x18/0x34 [ 4.225777] [ 4.225777] but task is already holding lock: [ 4.231615] ca09a3e4 (&tz->lock){+.+.}-{3:3}, at: thermal_zone_get_temp+0x38/0x6c [ 4.239121] [ 4.239121] other info that might help us debug this: [ 4.245655] Possible unsafe locking scenario: [ 4.245655] [ 4.251579] CPU0 [ 4.254031] ---- [ 4.256481] lock(&tz->lock); [ 4.259544] lock(&tz->lock); [ 4.262608] [ 4.262608] *** DEADLOCK *** [ 4.262608] [ 4.268533] May be due to missing lock nesting notation [ 4.268533] [ 4.275329] 4 locks held by kworker/0:3/54: [ 4.279517] #0: cb0066a8 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x224/0x808 [ 4.288241] #1: ca075f10 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x224/0x808 [ 4.296787] #2: cb1a48d8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x30/0x140 [ 4.304468] #3: ca09a3e4 (&tz->lock){+.+.}-{3:3}, at: thermal_zone_get_temp+0x38/0x6c [ 4.312408] [ 4.312408] stack backtrace: [ 4.316778] CPU: 0 PID: 54 Comm: kworker/0:3 Not tainted 5.8.0-rc3-00011-gf5e50bf4d3ef #42 [ 4.325048] Hardware name: Freescale i.MX7 Dual (Device Tree) [ 4.330809] Workqueue: events deferred_probe_work_func [ 4.335973] [<c0312384>] (unwind_backtrace) from [<c030c580>] (show_stack+0x10/0x14) [ 4.343734] [<c030c580>] (show_stack) from [<c079d7d8>] (dump_stack+0xe8/0x114) [ 4.351062] [<c079d7d8>] (dump_stack) from [<c03abf78>] (__lock_acquire+0xbfc/0x2cb4) [ 4.358909] [<c03abf78>] (__lock_acquire) from [<c03ae9c4>] (lock_acquire+0xf4/0x4e4) [ 4.366758] [<c03ae9c4>] (lock_acquire) from [<c10630fc>] (__mutex_lock+0xb0/0xaa8) [ 4.374431] [<c10630fc>] (__mutex_lock) from [<c1063b10>] (mutex_lock_nested+0x1c/0x24) [ 4.382452] [<c1063b10>] (mutex_lock_nested) from [<c0d932c0>] (thermal_zone_device_is_enabled+0x18/0x34) [ 4.392036] [<c0d932c0>] (thermal_zone_device_is_enabled) from [<c0d9da90>] (imx_get_temp+0x30/0x208) [ 4.401271] [<c0d9da90>] (imx_get_temp) from [<c0d97484>] (thermal_zone_get_temp+0x4c/0x6c) [ 4.409640] [<c0d97484>] (thermal_zone_get_temp) from [<c0d93df0>] (thermal_zone_device_update+0x8c/0x258) [ 4.419310] [<c0d93df0>] (thermal_zone_device_update) from [<c0d9401c>] (thermal_zone_device_set_mode+0x60/0x88) [ 4.429500] [<c0d9401c>] (thermal_zone_device_set_mode) from [<c0d9e1d4>] (imx_thermal_probe+0x3e4/0x578) [ 4.439082] [<c0d9e1d4>] (imx_thermal_probe) from [<c0a78388>] (platform_drv_probe+0x48/0x98) [ 4.447622] [<c0a78388>] (platform_drv_probe) from [<c0a7603c>] (really_probe+0x218/0x348) [ 4.455903] [<c0a7603c>] (really_probe) from [<c0a76278>] (driver_probe_device+0x5c/0xb4) [ 4.464098] [<c0a76278>] (driver_probe_device) from [<c0a743bc>] (bus_for_each_drv+0x58/0xb8) [ 4.472638] [<c0a743bc>] (bus_for_each_drv) from [<c0a75db0>] (__device_attach+0xd4/0x140) [ 4.480919] [<c0a75db0>] (__device_attach) from [<c0a750b0>] (bus_probe_device+0x88/0x90) [ 4.489112] [<c0a750b0>] (bus_probe_device) from [<c0a75564>] (deferred_probe_work_func+0x68/0x98) [ 4.498088] [<c0a75564>] (deferred_probe_work_func) from [<c0369988>] (process_one_work+0x2e0/0x808) [ 4.507237] [<c0369988>] (process_one_work) from [<c036a150>] (worker_thread+0x2a0/0x59c) [ 4.515432] [<c036a150>] (worker_thread) from [<c0372208>] (kthread+0x16c/0x178) [ 4.522843] [<c0372208>] (kthread) from [<c0300174>] (ret_from_fork+0x14/0x20) [ 4.530074] Exception stack(0xca075fb0 to 0xca075ff8) [ 4.535138] 5fa0: 00000000 00000000 00000000 00000000 [ 4.543328] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 4.551516] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 -- <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook | <http://twitter.com/#!/linaroorg> Twitter | <http://www.linaro.org/linaro-blog/> Blog