Re: BUG: net-next (7.0-rc6 based and later) fails to boot on Jetson Xavier NX

[Robin Murphy <robin.murphy@arm.com>]

On 2026-04-08 5:16 pm, Russell King (Oracle) wrote:
> On Wed, Apr 08, 2026 at 05:08:34PM +0100, Russell King (Oracle) wrote:
>> The rebase is still progressing, but it's landed on:
>>
>> c7d812e33f3e dmaengine: xilinx: xilinx_dma: Fix unmasked residue subtraction

FWIW I don't see a Tegra having the Xilinx IP in it anyway - judging by 
the DT it has their own tegra-gpcdma engine...

There's a fair chance this could be 90c5def10bea ("iommu: Do not call 
drivers for empty gathers"), which JonH also reported causing boot 
issues on Tegras - in short, SMMU TLB maintenance may not be completed 
properly which could lead to recycled DMA addresses causing exactly this 
kind of random memory corruption. I CC'd you on a patch:

https://lore.kernel.org/linux-iommu/20260408162846.GE3357077@nvidia.com/T/#t

Thanks,
Robin.

>>
>> and while this boots to a login prompt, it spat out a BUG():
>>
>> BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591
>> in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 56, name: kworker/u24:3
>> preempt_count: 0, expected: 0
>> RCU nest depth: 0, expected: 0
>> 3 locks held by kworker/u24:3/56:
>>   #0: ffff000080042148 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x184/0x780
>>   #1: ffff80008299bdf8 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work+0x1ac/0x780
>>   #2: ffff0000808b48f8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x2c/0x188
>> irq event stamp: 10872
>> hardirqs last  enabled at (10871): [<ffff80008013a410>] ktime_get+0x130/0x180
>> hardirqs last disabled at (10872): [<ffff800080d61ac8>] _raw_spin_lock_irqsave+0x84/0x88
>> softirqs last  enabled at (9216): [<ffff80008002807c>] fpsimd_save_and_flush_current_state+0x3c/0x80
>> softirqs last disabled at (9214): [<ffff800080028098>] fpsimd_save_and_flush_current_state+0x58/0x80
>> CPU: 5 UID: 0 PID: 56 Comm: kworker/u24:3 Not tainted 7.0.0-rc1-bisect+ #654 PREEMPT
>> Hardware name: NVIDIA NVIDIA Jetson Xavier NX Developer Kit/Jetson, BIOS 6.0-37391689 08/28/2024
>> Workqueue: events_unbound deferred_probe_work_func
>> Call trace:
>>   show_stack+0x18/0x30 (C)
>>   dump_stack_lvl+0x6c/0x94
>>   dump_stack+0x18/0x24
>>   __might_resched+0x154/0x220
>>   __might_sleep+0x48/0x80
>>   __mutex_lock+0x48/0x800
>>   mutex_lock_nested+0x24/0x30
>>   pinmux_disable_setting+0x9c/0x180
>>   pinctrl_commit_state+0x5c/0x260
>>   pinctrl_pm_select_idle_state+0x4c/0xa0
>>   tegra_i2c_runtime_suspend+0x2c/0x3c
>>   pm_generic_runtime_suspend+0x2c/0x44
>>   __rpm_callback+0x48/0x1ec
>>   rpm_callback+0x74/0x80
>>   rpm_suspend+0xec/0x630
>>   rpm_idle+0x2c0/0x420
>>   __pm_runtime_idle+0x44/0x160
>>   tegra_i2c_probe+0x2e4/0x640
>>   platform_probe+0x5c/0xa4
>>   really_probe+0xbc/0x2c0
>>   __driver_probe_device+0x78/0x120
>>   driver_probe_device+0x3c/0x160
>>   __device_attach_driver+0xbc/0x160
>>   bus_for_each_drv+0x70/0xb8
>>   __device_attach+0xa4/0x188
>>   device_initial_probe+0x50/0x54
>>   bus_probe_device+0x38/0xa4
>>   deferred_probe_work_func+0x90/0xcc
>>   process_one_work+0x204/0x780
>>   worker_thread+0x1c8/0x36c
>>   kthread+0x138/0x144
>>   ret_from_fork+0x10/0x20
>>
>> This is reproducible.
> 
> I've just realised that it's the Tegra I2C bug that is already known
> about, but took ages to be fixed in mainline - it's unrelated to the
> memory corruption, so can be ignored. Sorry for the noise.
>