Re: [PATCH] spi: remove return value check of debugfs_create_dir() - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Mark Brown <broonie@kernel.org>
Cc: Peter Enderborg <peter.enderborg@sony.com>,
	Yingsha Xu <ysxu@hust.edu.cn>,
	Serge Semin <fancer.lancer@gmail.com>,
	linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] spi: remove return value check of debugfs_create_dir()
Date: Mon, 24 Apr 2023 15:08:03 +0200	[thread overview]
Message-ID: <2023042423-ice-rice-e3d3@gregkh> (raw)
In-Reply-To: <55ab40bb-8b3e-496d-bf45-6c4ebd01e43f@sirena.org.uk>

On Mon, Apr 24, 2023 at 02:00:14PM +0100, Mark Brown wrote:
> On Mon, Apr 24, 2023 at 02:53:12PM +0200, Greg Kroah-Hartman wrote:
> > On Mon, Apr 24, 2023 at 01:32:14PM +0100, Mark Brown wrote:
> 
> > > There's issues with partially created debugfs structures getting in the
> > > way of people trying to debug things, just completely ignoring all
> > > errors can create confusion as the diagnostic information people believe
> > > is being shown to them ends up being partial or mistructured without any
> > > indication that this has happened.
> 
> > How do you end up with partially created debugfs structures?
> 
> The ones I've seen have been name collisions caused by for example the
> debugfs structure created being flatter than the device model structure,
> though obviously something unanticipated could come up.

Sure name collisions will happen, when people aren't precise about how
they create their debugfs files (I just had to insist on this type of
fixups for a USB patch last week.)  But, debugfs failures should never
stop a driver from working properly, only the debugging functionalities.
So there's no need to error out from debugfs errors as the only one
affected is the kernel developer involved, not users.

thanks,

greg k-h