From: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
To: Mark Brown <broonie@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
David Lechner <david@lechnology.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] regmap: do not call regmap_debugfs_init() from regmap_attach_dev()
Date: Mon, 26 Jul 2021 14:01:51 +0200 [thread overview]
Message-ID: <7b54590fddf167744fa2574d8815130608f8e063.camel@ew.tq-group.com> (raw)
In-Reply-To: <20210726114751.GE4670@sirena.org.uk>
On Mon, 2021-07-26 at 12:47 +0100, Mark Brown wrote:
> * PGP Signed by an unknown key
>
> On Mon, Jul 26, 2021 at 09:36:27AM +0200, Matthias Schiffer wrote:
> > regmap_debugfs_init() should never be called twice for the same regmap,
> > as it initializes various fields of the regmap struct, including list
> > heads and mutices. A visible symptom are messages like:
> >
> > debugfs: Directory 'dummy-iomuxc-gpr@20e4000' with parent 'regmap'
> > already present!
> >
> > This happened whenever regmap_attach_dev() was called for an existing
> > regmap. Remove the call from regmap_attach_dev() and change
> > __regmap_init() so that regmap_debugfs_init() is called exactly once.
>
> The use case for regmap_attach_dev() is that there was no device when
> the regmap was initially instantiated due to it running very early, we
> want to attach the device when we figure out what it is which includes
> setting up the debugfs stuff. Whatever is managing to call this with
> the same device as has already been set is clearly not that use case.
>
>
Hi Mark,
I'm not talking about a case where regmap_attach_dev() is called when
there is already a device attached; as far as I can tell such a thing
does not happen in current kernel code.
Please have a look at the commit in the Fixes: tag. The duplicate
regmap_debugfs_init() happens even when no device was passed in
__regmap_init(), so the regmap_attach_dev() is the first time a device
it attached.
next prev parent reply other threads:[~2021-07-26 12:02 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-26 7:36 [PATCH] regmap: do not call regmap_debugfs_init() from regmap_attach_dev() Matthias Schiffer
2021-07-26 11:47 ` Mark Brown
2021-07-26 12:01 ` Matthias Schiffer [this message]
2021-07-26 12:11 ` Mark Brown
2021-07-26 12:18 ` Matthias Schiffer
2021-07-26 18:48 ` Mark Brown
2021-07-27 12:24 ` (EXT) " Matthias Schiffer
2021-07-27 17:08 ` Mark Brown
2021-07-28 9:13 ` Matthias Schiffer
2021-07-26 12:00 ` Mark Brown
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