[PATCH v3] i2c: lpi2c: cache peripheral clock rate

[Sverdlin, Alexander]

Hello Alexander!

On Mon, 2023-05-15 at 14:32 +0200, Alexander Stein wrote:
> > stack backtrace:
> > CPU: 1 PID: 2238 Comm: xxxxxxx Tainted: G           O     
> > 5.15.71+git8e43aee #1
> > Hardware name: Siemens PXC5.E24 (DT)
> > Call trace:
> >   dump_backtrace+0x0/0x1d4
> >   show_stack+0x20/0x2c
> >   dump_stack_lvl+0x8c/0xb8
> >   dump_stack+0x18/0x34
> >   print_circular_bug+0x1f8/0x200
> >   check_noncircular+0x130/0x144
> >   __lock_acquire+0x12a4/0x20a0
> >   lock_acquire.part.0+0xe0/0x230
> >   lock_acquire+0x68/0x84
> >   __mutex_lock+0xa8/0x4d0
> >   mutex_lock_nested+0x48/0x54
> >   __setup_irq+0xbc/0x8bc
> >   request_threaded_irq+0xf4/0x1b4
> >   devm_request_threaded_irq+0x88/0x104
> >   lpi2c_runtime_resume+0x70/0xe4
> 
> It seems your (possible) deadlock is triggered along
> devm_request_irq() during 
> resume.

You are right! Thank you for looking into this!

> As mainline just enables the clocks, there is nothing we can do here.
> Your 
> patch still is sensible, can you send a new version with the review
> addressed? 

Sure, I'll do!

-- 
Alexander Sverdlin
Siemens AG
www.siemens.com