RE: [EXT] Re: [PATCH V2 1/4] spi: lpspi: Fix kernel warning dump when probe fail after calling spi_register

From: Clark Wang
Date: Thu Jul 30 2020 - 22:01:19 EST



> -----Original Message-----
> From: Mark Brown <broonie@xxxxxxxxxx>
> Sent: Monday, July 27, 2020 19:11
> To: Clark Wang <xiaoning.wang@xxxxxxx>
> Cc: linux-spi@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [EXT] Re: [PATCH V2 1/4] spi: lpspi: Fix kernel warning dump when
> probe fail after calling spi_register
>
> On Mon, Jul 27, 2020 at 11:14:46AM +0800, Clark Wang wrote:
> > Calling devm_spi_register_controller() too early will cause problem.
> > When probe failed occurs after calling devm_spi_register_controller(),
> > the call of spi_controller_put() will trigger the following warning dump.
> >
> > [ 2.092138] ------------[ cut here ]------------
> > [ 2.096876] kernfs: can not remove 'uevent', no directory
> > [ 2.102440] WARNING: CPU: 0 PID: 181 at fs/kernfs/dir.c:1503
> kernfs_remove_by_name_ns+0xa0/0xb0
> > [ 2.111142] Modules linked in:
> > [ 2.114207] CPU: 0 PID: 181 Comm: kworker/0:7 Not tainted 5.4.24-05024-
> g775c6e8a738c-dirty #1314
> > [ 2.122991] Hardware name: Freescale i.MX8DXL EVK (DT)
> > [ 2.128141] Workqueue: events deferred_probe_work_func
>
> Please think hard before including complete backtraces in upstream reports,
> they are very large and contain almost no useful information relative to their
> size so often obscure the relevant content in your message. If part of the
> backtrace is usefully illustrative (it often is for search engines if nothing else)
> then it's usually better to pull out the relevant sections.

Hi Mark,

Thank you very much for reminding.
I will remove the redundant part when I meet similar situations in the future. ð

Best Regards,
Clark Wang