From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brownell Subject: Re: [PATCH 3/6] i2c: ignore active clients detaching during adapter removal. Date: Thu, 5 Feb 2009 16:02:43 -0800 Message-ID: <200902051602.44036.david-b@pacbell.net> References: <1233840973-13268-1-git-send-email-giometti@linux.it> <1233840973-13268-3-git-send-email-giometti@linux.it> <1233840973-13268-4-git-send-email-giometti@linux.it> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1233840973-13268-4-git-send-email-giometti-k2GhghHVRtY@public.gmane.org> Content-Disposition: inline Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rodolfo Giometti Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jean Delvare , Kumar Gala , Peter Korsgaard List-Id: linux-i2c@vger.kernel.org On Thursday 05 February 2009, Rodolfo Giometti wrote: >=20 > When we are removing an adapter we decide to ignore any active client > detaching faults for two reasons: >=20 > 1) one (or more) active client may be switched off, so it cannot > =A0 =A0replay to the "adapter removed" event. >=20 > 2) it shouldn't happen, and even if it happens it may be due a bus > =A0 =A0fault which can be resolved by resetting the adapter (most of = them > =A0 =A0can be resetted simply by rmmod and then insmod the module aga= in). This bothers me. If the client can't detach, it can't; there may be all kinds of chaos introduced by trying to fake success in such cases. Like resources that suddenly just vanish, leaving breakage in their wake. If this is a shutdown() path, where it's basically just a polite driver notification, that's one thing. But I2C gets used as a system control bus, so this sort of "ignore the errors" stuff worries me a lot. - Dave