From: "ext Shilimkar, Santosh" <santosh.shilimkar@xxxxxx> Subject: RE: [RFC][PATCH 1/1] ARM: Add initial hibernation support Date: Fri, 16 Jul 2010 10:48:00 +0200 > Hiroshi, >> -----Original Message----- >> From: linux-omap-owner@xxxxxxxxxxxxxxx [mailto:linux-omap- >> owner@xxxxxxxxxxxxxxx] On Behalf Of Russell King - ARM Linux >> Sent: Friday, July 16, 2010 1:23 PM >> To: Hiroshi DOYU >> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; pavel@xxxxxx; >> khilman@xxxxxxxxxxxxxxxxxxx; Reddy, Teerth; linux-pm@xxxxxxxxxxxx >> foundation.org; Yoshiya.Hirase@xxxxxxxxx; linux-omap@xxxxxxxxxxxxxxx >> Subject: Re: [RFC][PATCH 1/1] ARM: Add initial hibernation support >> >> On Thu, Jul 15, 2010 at 12:08:07PM +0300, Hiroshi DOYU wrote: >> > From: ext Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> >> > Subject: Re: [RFC][PATCH 1/1] ARM: Add initial hibernation support >> > Date: Thu, 15 Jul 2010 10:41:18 +0200 >> > >> > > On Thu, Jul 15, 2010 at 08:34:50AM +0300, Hiroshi DOYU wrote: >> > >> Russell, would it be possible to put this into your next merge queue? >> > > >> > > I think it needs quite a bit of rework - I certainly don't like all >> > > those CP15 register accesses there - that's asking for lots of ifdefs >> > > to spring up as more CPUs are supported. >> > > >> > > Eg, what about ensuring that state such as iWMMXt on PXA CPUs is >> > > properly restored? >> > >> > Right. This arch specific part can be something like >> > "suspend-v[3-7].S" to accomodate those differences >> >> It's not quite that simple - things like iWMMXt aren't part of the ARM >> arch specs. >> >> > > We already have code which knows what needs to be saved across a >> > > power-off transition - its what we use for our normal suspend/resume >> > > functionality, so we should look at re-using that code for hibernate >> > > as well. We really don't want to be maintaining two sets of code >> > > doing the same thing. >> > >> > Could you explain which code you're refering for the existing one? >> >> The code which handles saving state for the existing suspend/resume >> support. This code already saves the necessary state from CP15 and >> any other state which needs to be saved prior to putting the system >> into low power mode. >> >> Every machine class which supports suspend today has their own chunk >> of code which does this, normally called something like sleep.S >> > When this getting developed in TI, we had one more concern about handling > the trustzone part for the CP15 resgiters. > This patch will hang on restoration on some devices implementing trustzone. Thanks for the info. I think that this trustzone issue and PXA part can be revisited later once the basic stuff is accepted. _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
