From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sonny Rao Subject: Re: [linux-pm] [RFC][PATCH] Enable async suspend/resume of i2c devices Date: Wed, 6 Apr 2011 16:08:32 -0700 Message-ID: References: <20110406095240.410b4e7e@endymion.delvare> <20110406223123.GA5297@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20110406223123.GA5297-yzvPICuk2AATkU/dhu1WVueM+bqZidxxQQ4Iyu8u01E@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Mark Brown Cc: Alan Stern , Jean Delvare , "Rafael J. Wysocki" , linux-pm-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, "Ben Dooks (embedded platforms)" List-Id: linux-i2c@vger.kernel.org On Wed, Apr 6, 2011 at 3:31 PM, Mark Brown wrote: > On Wed, Apr 06, 2011 at 10:49:17AM -0400, Alan Stern wrote: > >> Neither is the case. =A0For these subsystems, the PM dependencies _a= re_ >> known. > > ... > >> Now, I have no idea what the situation is with regard to I2C... > > You definitely don't know *anything* about the relationships for I2C, > especially in embedded systems. > Would it be okay to enable this on a per-device basis where it is known to be safe? I started out doing it like this, but I didn't like the way the patch = looked because it ended up having to call this function twice -- once on the i= 2c master device and once on it's client devices (and actually a third tim= e because it had another struct dev for the industrial IO device). So, that seemed pretty ugly. Also, it didn't seem to match the usage of device_enable_async_suspend(= ) in other parts of the kernel where it was used on whole subsystems. Sonny