Re: [PATCH 01/14] parport: return value of attach and parport_register_driver

From: Dan Carpenter <dan.carpenter@oracle.com>
To: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Cc: devel@driverdev.osuosl.org,
	Rodolfo Giometti <giometti@enneenne.com>,
	linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org,
	Arnd Bergmann <arnd@arndb.de>, Wolfram Sang <wsa@the-dreams.de>,
	Takashi Iwai <tiwai@suse.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	alsa-devel@alsa-project.org,
	"James E.J. Bottomley" <JBottomley@parallels.com>,
	Jaroslav Kysela <perex@perex.cz>, Mark Brown <broonie@kernel.org>,
	linux-i2c@vger.kernel.org, Willy Tarreau <willy@meta-x.org>,
	linux-spi@vger.kernel.org, netdev@vger.kernel.org,
	Jean Delvare <jdelvare@suse.de>
Subject: Re: [PATCH 01/14] parport: return value of attach and parport_register_driver
Date: Wed, 8 Apr 2015 15:27:37 +0300	[thread overview]
Message-ID: <20150408122737.GK10964@mwanda> (raw)
In-Reply-To: <20150408115010.GA11153@sudip-PC>

On Wed, Apr 08, 2015 at 05:20:10PM +0530, Sudip Mukherjee wrote:
> On Wed, Apr 08, 2015 at 02:38:32PM +0300, Dan Carpenter wrote:
> > 1) We can't apply this patch on its own so this way of breaking up the
> > patches doesn't work.
> yes, if the first patch is reverted for any reason all the others need
> to be reverted also. so then everything in one single patch?

The problem is that patch 1/1 breaks the build.  The rule is that we
should be able to apply part of a patch series and nothing breaks.  If
we apply the patch series out of order than things break that's our
problem, yes.  But if we apply only 1/1 and it breaks, that's a problem
with the series.

> > 
> > 2) I was thinking that all the ->attach() calls would have to succeed or
> > we would bail.  Having some of them succeed and some fail doesn't seem
> > like it will simplify the driver code very much.  But I can also see
> > your point.  Hm...

My other issue with this patch series which is related to #2 is that
it's not clear that anyone is checking the return value and doing
correct things with it.

Hopefully, when we use the attach_ret() approach then it will be more
clear if/how the return value is useful.

regards,
dan carpenter