Messages in this thread | | | Date | Thu, 13 Oct 2011 22:18:07 +0800 | Subject | Re: [PATCH 2/5] drivercore: Add driver probe deferral mechanism | From | Ming Lei <> |
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CC Rafael and linux-pm
On Thu, Oct 13, 2011 at 12:09 PM, Grant Likely <grant.likely@secretlab.ca> wrote: > On Tue, Oct 11, 2011 at 08:29:18PM +0800, Ming Lei wrote: >> On Tue, Oct 11, 2011 at 1:37 AM, Andrei Warkentin <awarkentin@vmware.com> wrote: >> > Hi, >> > >> > ----- Original Message ----- >> >> From: "Greg KH" <greg@kroah.com> >> >> To: "Josh Triplett" <josh@joshtriplett.org> >> >> Cc: "G, Manjunath Kondaiah" <manjugk@ti.com>, linux-arm-kernel@lists.infradead.org, "Grant Likely" >> >> <grant.likely@secretlab.ca>, linux-omap@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, >> >> "Dilan Lee" <dilee@nvidia.com>, "Mark Brown" <broonie@opensource.wolfsonmicro.com>, Manjunath@jasper.es >> >> Sent: Saturday, October 8, 2011 11:55:02 AM >> >> Subject: Re: [PATCH 2/5] drivercore: Add driver probe deferral mechanism >> >> >> > >> > I'm a bit of a fly on the wall here, but I'm curious how this impacts suspend/resume. >> > device_initialize->device_pm_init are called from device_register, so certainly this >> > patch doesn't also ensure that the PM ordering matches probe ordering, which is bound >> > to break suspend, right? Was this ever tested with the OMAP target? Shouldn't the >> >> Inside device_add(), device_pm_add is called before bus_probe_device, >> so the patch can't change the device order in pm list, and just change >> the driver probe order. > > That's the way it works now, but can it be reworked? It would be
IMO, it depends on what shape you plan to rework. Currently, the deferred probe may found a resource dependency, but I am not sure that pm dependency is same with the resource dependency found during probe.
> possible to adjust the list order after successful probe. However, > I'm not clear on the ordering rules for the dpm_list. Right now it is > explicitly ordered to have parents before children, but as already > expressed, that doesn't accurately represent ordering constraints for > multiple device dependancies.
Maybe we should understand the correct model of the ordering constraints for the multiple device dependancies first, could you give a description or some examples about it?
> > So, reordering the list would probably require maintaining the > existing parent-child ordering constraint, but to also shift > devices (and any possible children?) to be after drivers that are > already probed. That alone will be difficult to implement and get > right, but maybe the constraints can be simplified. It needs some > further thought. > > g. > >
thanks, -- Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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