Re: [PATCHv3 5/5] misc: gehc-achc: new driver - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Sebastian Reichel <sebastian.reichel@collabora.com>
Cc: Mark Brown <broonie@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	Arnd Bergmann <arnd@arndb.de>, Shawn Guo <shawnguo@kernel.org>,
	Sascha Hauer <kernel@pengutronix.de>,
	Fabio Estevam <festevam@gmail.com>, Ian Ray <ian.ray@ge.com>,
	linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org,
	devicetree@vger.kernel.org, kernel@collabora.com
Subject: Re: [PATCHv3 5/5] misc: gehc-achc: new driver
Date: Fri, 28 May 2021 16:56:33 +0200	[thread overview]
Message-ID: <YLEEoV7d0rXn53n0@kroah.com> (raw)
In-Reply-To: <20210528140654.ffhetiikhde6seuo@earth.universe>

On Fri, May 28, 2021 at 04:06:54PM +0200, Sebastian Reichel wrote:
> > > +	/*
> > > +	 * The sysfs properties are bound to the dummy device, since the main device already
> > > +	 * uses drvdata assigned by the spidev driver.
> > > +	 */
> > > +	spi_set_drvdata(achc->ezport, achc);
> > > +	ret = devm_device_add_group(&achc->ezport->dev, &gehc_achc_attr_group);
> > 
> > You just raced and lost. Please use the default groups attribute for
> > your driver instead of this. Or properly attach it to the device some
> > other way, but what you have done here does not work, sorry.
> 
> I've been told the race got fixed from kernel POV?
> 
> https://lore.kernel.org/linux-input/20200521055400.GX89269@dtor-ws/

Kind of, it's still not good to do this "by hand", the driver core
should do it for you.

> If this is still an issue, I think most (all?) existing instances of
> devm_device_add_group() are a problem and it makes sense to have a
> checkpatch warning for it.

Yes, I need to just get rid of that call entirely.  I'll sick one of my
interns on it...

thanks,

greg k-h