From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: Shutting down PCI devices on suspend Date: Sun, 12 Dec 2004 21:18:10 +0100 Message-ID: <20041212201810.GE6272@elf.ucw.cz> References: <1102779460.5984.17.camel@tyrosine> <20041212164422.GD6286@elf.ucw.cz> <1102870863.5984.36.camel@tyrosine> <20041212171521.GC6272@elf.ucw.cz> <20041212192913.GB2661@neo.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20041212192913.GB2661-IBH0VoN/3vPQT0dZR+AlfA@public.gmane.org> Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Adam Belay Cc: Matthew Garrett , acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org Hi! > > Each PCI device is either: > > > > * supported -- it has a driver, we are okay > > > > * unsupported -- it should not be even turned on, right? > > > > * legacy, like VGA or IDE -- okay, we need drivers for those. You need > > to reinit them on resume, anyway, so.... > > > > ...yes, I think this is the best solution. > > Not necessarily. Most unsupported devices start in the on state. Also I > think it's difficult to see a consistent power management behavior/policy if > each driver is controlling it's devices' power state. I'd prefer to have > drivers saving and restoring device state and then having the bus driver > take care of the actual power state transitions. Why? Saving/restoring state is way more work than actual power state transitions. Provide nice helpers so that power state transitions are easy, but leave the work on the drivers, so that drivers may do something special if required. Ouch and btw linux-pm list exists where this stuff is debated... Pavel -- People were complaining that M$ turns users into beta-testers... ...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl! ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/