From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH 1/1] Remove suspend/resume functionality, add dynamic clocking Date: Tue, 15 Dec 2009 11:36:08 +0100 Message-ID: <20091215103608.GE17930@elf.ucw.cz> References: <083DF309106F364B939360100EC290F804F55C9225@eu1rdcrdc1wx030.exi.nxp.com> <20091126090252.GB12179@pengutronix.de> <083DF309106F364B939360100EC290F804F5659CFF@eu1rdcrdc1wx030.exi.nxp.com> <20091206084731.GE2766@ucw.cz> <20091206210225.GA20887@pengutronix.de> <20091206210739.GE10184@elf.ucw.cz> <083DF309106F364B939360100EC290F804F57A69FA@eu1rdcrdc1wx030.exi.nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <083DF309106F364B939360100EC290F804F57A69FA-SIPbe8o7cfX8DdpCu65jn8FrZmdRls4ZQQ4Iyu8u01E@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Kevin Wells Cc: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Russell King - ARM Linux , "linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , Vitaly Wool List-Id: linux-i2c@vger.kernel.org > > > > Are you sure its unneeded? What if someone attempts to suspend the > > > > system when a transaction is running? > > > That's exactly my question. I think the machine will suspend and the > > > transaction fail. So no suspend callback isn't optimal, but maybe OK?! > > > > Having failures just because suspend happened at wrong time is > > bad. .suspend() should just wait for end of transaction. > > I'm not sure what situation could actually occur that would suspend the > system in the middle of an I2C transaction. If an I2C transaction was > started and the CPU was suspended, this would appear to be a problem > outside the I2C driver itself. Would other I2C drivers have this similar > problem? Well, can the i2c transaction sleep? If so, suspend probably can come in the middle. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html