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 23:45:34 -0700 Message-ID: References: <20110406095240.410b4e7e@endymion.delvare> <20110406223123.GA5297@opensource.wolfsonmicro.com> <201104070722.44771.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <201104070722.44771.rjw-KKrjLPT3xs0@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Rafael J. Wysocki" Cc: Mark Brown , Alan Stern , Jean Delvare , 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 10:22 PM, Rafael J. Wysocki wrote: > On Thursday, April 07, 2011, Sonny Rao wrote: >> 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= _are_ >> >> known. >> > >> > ... >> > >> >> Now, I have no idea what the situation is with regard to I2C... >> > >> > You definitely don't know *anything* about the relationships for I= 2C, >> > especially in embedded systems. >> > >> >> Would it be okay to enable this on a per-device basis where it is >> known to be safe? > > Yes. Ok, I'll probably submit a patch for the specific case of the slow light sensor to the IIO guys later on, and if I find cases where we get wins on other I2C heavy platforms (like ARM netbooks) I'll send those out as device-specific changes as w= ell. > It is used by subsystems where dependencies between devices are known= to > generally follow the structure of the device hierarchy within the ker= nel > (i.e. they are well-defined buses with well-defined parents and child= ren). Ok, thanks for the explanation! Sonny