To: Adam Baker <linux@baker-net.org.uk>
Cc: rt2400-devel@lists.sourceforge.net, Ivo van Doorn <ivdoorn@gmail.com>,
       linux-kernel@vger.kernel.org, kernel-stuff@comcast.net
Subject: Re: [Rt2400-devel] [PATCH] rt2500usb - Don't claim 050d:705{0/a}
References: <alpine.DEB.0.99.0710241909250.18618@parag-desktop>
	<200710262039.17027.IvDoorn@gmail.com> <adamyu5zo88.fsf@cisco.com>
	<200710262058.56188.linux@baker-net.org.uk>
From: Roland Dreier <rdreier@cisco.com>
Date: Fri, 26 Oct 2007 13:05:54 -0700
In-Reply-To: <200710262058.56188.linux@baker-net.org.uk> (Adam Baker's message of "Fri, 26 Oct 2007 20:58:56 +0100")
Message-ID: <adaejfhzlnh.fsf@cisco.com>
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 > The function that is returning ENODEV is the driver probe function. According 
 > to Documentation/DocBook/writing_usb_driver/ch03.html when that function is 
 > called 
 > 
 > "The driver now needs to verify that this device is actually one that it can 
 > accept. If so, it returns 0. If not, or if any error occurs during 
 > initialization, an errorcode (such as -ENOMEM or -ENODEV) is returned from 
 > the probe function."
 > 
 > It isn't a device the driver can accept so it returns -ENODEV

That's all true but irrelevant.  That error return isn't propagated
back to userspace when it runs modprobe (and in fact it *can't* be
sanely returned to userspace -- what do you do if the probe function
succeeds for two devices and fails for a third?).  So there's not
really any way for userspace to loop through a list of modules until
one succeeds.
-
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