lkml.org 
[lkml]   [2022]   [Jun]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/3] thermal/drivers/tegra: Remove get_trend function
On 6/29/22 02:35, Dmitry Osipenko wrote:
> On 6/28/22 21:43, Guenter Roeck wrote:
>> On Tue, Jun 28, 2022 at 08:10:30AM -0700, Guenter Roeck wrote:
>>> On Tue, Jun 28, 2022 at 02:44:31PM +0300, Dmitry Osipenko wrote:
>>>> On 6/28/22 11:41, Daniel Lezcano wrote:
>>>>>
>>>>> Thierry, Dmitry,
>>>>>
>>>>> are fine with this patch?
>>>>
>>>> Seems should be good. I couldn't test it using recent the linux-next
>>>> because of a lockup in LM90 driver. There were quite a lot of changes in
>>>> LM90 recently, adding Guenter.
>>>>
>>>
>>> Weird, I tested those changes to death with real hardware, and I don't
>>> see a code path where the mutex can be left in blocked state unless the
>>> underlying i2c driver locks up for some reason. What is the platform,
>>> and can you point me to the devicetree file ? Also, is there anything
>>> else lm90 or i2c related in the kernel log ?
>>>
>>
>> Follow-up question: I see that various Tegra systems use lm90 compatible
>> chips, and the interrupt line is in general wired up. Can you check if
>> you get lots of interrupts on that interrupt line ? Also, can you check
>> what happens if you read hwmon attributes directly ?
>
> The number of interrupt fires is okay. It's a Nexus 7 Tegra30 tablet
> device that I'm using for the testing.
>
> Today I enabled the lockdep and it immediately showed where the problem is:
>

Yes, that is an obvious problem. Thanks a lot for testing!

Guenter

> ======================================================
> WARNING: possible circular locking dependency detected
> 5.19.0-rc4-next-20220628-00002-g94e5dbbe1c58-dirty #24 Not tainted
> ------------------------------------------------------
> irq/91-lm90/130 is trying to acquire lock:
> c27ba380 (&tz->lock){+.+.}-{3:3}, at: thermal_zone_device_update+0x2c/0x64
>
> but task is already holding lock:
> c27b42c8 (&data->update_lock){+.+.}-{3:3}, at: lm90_irq_thread+0x2c/0x68
>
> which lock already depends on the new lock.
>
>
> the existing dependency chain (in reverse order) is:
>
> -> #1 (&data->update_lock){+.+.}-{3:3}:
> __mutex_lock+0x9c/0x984
> mutex_lock_nested+0x2c/0x34
> lm90_read+0x44/0x3e8
> hwmon_thermal_get_temp+0x58/0x8c
> of_thermal_get_temp+0x38/0x44
> thermal_zone_get_temp+0x5c/0x7c
> thermal_zone_device_update.part.0+0x48/0x5fc
> thermal_zone_device_set_mode+0xa0/0xe4
> thermal_zone_device_enable+0x1c/0x20
> thermal_zone_of_sensor_register+0x18c/0x19c
> devm_thermal_zone_of_sensor_register+0x68/0xa4
> __hwmon_device_register+0x704/0x91c
> hwmon_device_register_with_info+0x6c/0x80
> devm_hwmon_device_register_with_info+0x78/0xb4
> lm90_probe+0x618/0x8c0
> i2c_device_probe+0x170/0x2e0
> really_probe+0xd8/0x300
> __driver_probe_device+0x94/0xf4
> driver_probe_device+0x40/0x118
> __device_attach_driver+0xc8/0x10c
> bus_for_each_drv+0x90/0xdc
> __device_attach+0xbc/0x1d4
> device_initial_probe+0x1c/0x20
> bus_probe_device+0x98/0xa0
> deferred_probe_work_func+0x8c/0xbc
> process_one_work+0x2b8/0x774
> worker_thread+0x17c/0x56c
> kthread+0x108/0x13c
> ret_from_fork+0x14/0x28
> 0x0
>
> -> #0 (&tz->lock){+.+.}-{3:3}:
> __lock_acquire+0x173c/0x3198
> lock_acquire+0x128/0x3f0
> __mutex_lock+0x9c/0x984
> mutex_lock_nested+0x2c/0x34
> thermal_zone_device_update+0x2c/0x64
> hwmon_notify_event+0x128/0x138
> lm90_update_alarms_locked+0x35c/0x3b8
> lm90_irq_thread+0x38/0x68
> irq_thread_fn+0x2c/0x8c
> irq_thread+0x190/0x29c > kthread+0x108/0x13c
> ret_from_fork+0x14/0x28
> 0x0
>
> other info that might help us debug this:
>
> Possible unsafe locking scenario:
>
> CPU0 CPU1
> ---- ----
> lock(&data->update_lock);
> lock(&tz->lock);
> lock(&data->update_lock);
> lock(&tz->lock);
>
> *** DEADLOCK ***
>
> 1 lock held by irq/91-lm90/130:
> #0: c27b42c8 (&data->update_lock){+.+.}-{3:3}, at:
> lm90_irq_thread+0x2c/0x68
>
> stack backtrace:
> CPU: 1 PID: 130 Comm: irq/91-lm90 Not tainted
> 5.19.0-rc4-next-20220628-00002-g94e5dbbe1c58-dirty #24
> Hardware name: NVIDIA Tegra SoC (Flattened Device Tree)
> Backtrace:
> dump_backtrace from show_stack+0x20/0x24
> r7:c33d1b60 r6:00000080 r5:60000093 r4:c168c6a4
> show_stack from dump_stack_lvl+0x68/0x98
> dump_stack_lvl from dump_stack+0x18/0x1c
> r7:c33d1b60 r6:c20328cc r5:c203c700 r4:c20328cc
> dump_stack from print_circular_bug+0x2ec/0x33c
> print_circular_bug from check_noncircular+0x104/0x168
> r10:c1a14cc8 r9:c33d1240 r8:00000001 r7:00000000 r6:dfc3dcc0 r5:c33d1b60
> r4:c33d1b80
> check_noncircular from __lock_acquire+0x173c/0x3198
> r7:c33d1b80 r6:c202bc98 r5:c33d1b60 r4:c21d92ac
> __lock_acquire from lock_acquire+0x128/0x3f0
> r10:60000013 r9:00000000 r8:00000000 r7:00000000 r6:dfc3dd40 r5:c19ac688
> r4:c19ac688
> lock_acquire from __mutex_lock+0x9c/0x984
> r10:c27ba380 r9:00000000 r8:c21d92ac r7:c33d1240 r6:00000000 r5:00000000
> r4:c27ba348
> __mutex_lock from mutex_lock_nested+0x2c/0x34
> r10:c27b4000 r9:00000000 r8:dfc3de87 r7:00000000 r6:c27ba348 r5:00000000
> r4:c27ba000
> mutex_lock_nested from thermal_zone_device_update+0x2c/0x64
> thermal_zone_device_update from hwmon_notify_event+0x128/0x138
> r7:00000000 r6:00000000 r5:c2d23ea4 r4:c33fd040
> hwmon_notify_event from lm90_update_alarms_locked+0x35c/0x3b8
> r8:c27b4378 r7:c2d23c08 r6:00000020 r5:00000000 r4:c27b4240
> lm90_update_alarms_locked from lm90_irq_thread+0x38/0x68
> r9:c01c2814 r8:00000001 r7:c33d2240 r6:c27b4290 r5:c27b4240 r4:c33fc200
> lm90_irq_thread from irq_thread_fn+0x2c/0x8c
> r7:c33d2240 r6:c27b4000 r5:c33d1240 r4:c33fc200
> irq_thread_fn from irq_thread+0x190/0x29c
> r7:c33d2240 r6:c33fc224 r5:c33d1240 r4:00000000
> irq_thread from kthread+0x108/0x13c
> r10:00000000 r9:df9ddbf4 r8:c31d2200 r7:c33fc200 r6:c01c2710 r5:c33d1240
> r4:c33fc240
> kthread from ret_from_fork+0x14/0x28
>

\
 
 \ /
  Last update: 2022-06-29 14:57    [W:0.079 / U:0.792 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site