From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tero Kristo <t-kristo@ti.com>
Subject: Re: [PATCHv2 14/19] ARM: OMAP4: wakeupgen: enable clocks for
 save_secure_all
Date: Wed, 30 May 2012 11:44:47 +0300
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To: "Menon, Nishanth" <nm@ti.com>
Cc: Kevin Hilman <khilman@ti.com>, paul@pwsan.com, linux-omap@vger.kernel.org, Benoit Cousson <b-cousson@ti.com>, linux-arm-kernel@lists.infradead.org

On Tue, 2012-05-29 at 15:48 -0500, Menon, Nishanth wrote:
> On Tue, May 29, 2012 at 3:15 PM, Kevin Hilman <khilman@ti.com> wrote:
> > Tero Kristo <t-kristo@ti.com> writes:
> >
> >> On Wed, 2012-05-16 at 17:06 -0700, Kevin Hilman wrote:
> >>> +Benoit
> >>>
> >>> Tero Kristo <t-kristo@ti.com> writes:
> >>>
> >>> > save_secure_all needs l3_main_3_ick and l4_secure_clkdm enabled,
> >>> > otherwise the secure ROM code will crash.
> >>> >
> >>> > Signed-off-by: Tero Kristo <t-kristo@ti.com>
> >>>
> >>> I think I mentioned this already (I'm already lost in what I've said for
> >>> thisseries), but I don't think the secure RAM stuff belongs in the
> >>> wakeupgen driver.
> >>
> >> As mentioned, save_secure_all saves:
> >> - secure RAM
> >> - GIC registers
> >> - some other mysterious stuff
> >>
> >> Attempting to do separate saves for secure RAM + GIC hang the device
> >> during wakeup, in addition to being really inefficient (secure API calls
> >> are expensive.)
> >
> > I guess my comment wasn't that this isn't needed, but that it doesn't
> > seem to belong in the wakeupgen base (which should probably converted
> > into a real driver.)
> >
> > Seems better to have this stuff in the secure code, maybe omap-secure.c?
> >
> 
> Perhaps OFF mode notifier might help best here. In addition - it might
> be safer to protect all calls with clkdm_wakeup around
> secure_dispatcher instead of just the save_secure_all.. ROM code is
> not smart enough around it.
> an completely safe version used by security driver can be found here:
> http://git.omapzoom.org/?p=kernel/omap.git;a=blob;f=security/smc/tf_comm_mshield.c;h=b5279fef0fa400438a57b3941af13d965e983bf0;hb=p-android-omap-3.0#l253
> 

Thats true... the secure driver in mainline kernel is rather a stub.
Previous version of this patch actually had clkdm_wakeup around every
call to dispatcher, I just optimized it away. I can add it back in the
next version if you think that is better.

-Tero