linux-kernel - Re: [PATCH] regmap: no need to check return value of debugfs

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Message-ID: <20190122164352.GA24734@kroah.com>
Date:   Tue, 22 Jan 2019 17:43:52 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     Mark Brown <broonie@...nel.org>
Cc:     linux-kernel@...r.kernel.org,
        "Rafael J. Wysocki" <rafael@...nel.org>
Subject: Re: [PATCH] regmap: no need to check return value of debugfs_create
 functions

On Tue, Jan 22, 2019 at 04:38:26PM +0000, Mark Brown wrote:
> On Tue, Jan 22, 2019 at 05:08:57PM +0100, Greg Kroah-Hartman wrote:
> > On Tue, Jan 22, 2019 at 03:56:06PM +0000, Mark Brown wrote:
> 
> > > Given that all the rest of the function is doing is further debugfs
> > > operations and when it fails people trying to use the debugfs do welcome
> > > some diagnostics I'm not sure that's particularly helpful.
> 
> > The only way it will fail is if we are out of memory.  And you are in a
> > bigger mess then, no one cares about debugfs calls, just make them and
> > move on, you should never care about the result of such a call.
> 
> No, it also fails if there's already something with the same name in
> debugfs which can happen as as a result of configuration.  This gets
> confusing for users, they see the debugfs files they're expecting but
> the contents don't match up at all.

How can you allow a duplicate name for the other regmap stuff?  Will
that not also cause a collision somewhere else?

Anyway, if this is that big of a problem, ok, but then your code will
run differently if debugfs is enabled or not, which isn't ok.  Don't
rely on debugfs to do your name filtering for you :)

thanks,

greg k-h