[PATCHv2 10/19] ARM: OMAP4: PM: Work-around for ROM code BUG of IVAHD/TESLA

[Tero Kristo]

On Wed, 2012-05-16 at 16:07 -0700, Kevin Hilman wrote:
> On 05/16/2012 04:05 PM, Kevin Hilman wrote:
> > Tero Kristo<t-kristo at ti.com>  writes:
> >
> >> From: Santosh Shilimkar<santosh.shilimkar at ti.com>
> >>
> >> The ROM BUG is when MPU Domain OFF wake up sequence that can compromise
> >> IVA and Tesla execution.
> >>
> >> At wakeup from MPU OFF on HS device only (not GP device), when
> >> restoring the Secure RAM, the ROM Code reconfigures the clocks the
> >> same way it is done at Cold Reset.
> >
> > Ouch.
> >
> >> The IVAHD Clocks and Power Domain settings are:
> >> 	IVAHD_CM2 IVAHD_CLKCTRL_MODULE_MODE = DISABLE
> >> 	IVAHD_CM2 SL2_CLKCTRL_MODULE_MODE = DISABLE
> >> 	IVAHD_CM2 SL2_CLKSTCTRL_CLKTRCTRL = HW_AUTO
> >> 	IVAHD_PRM IVAHD_PWRSTCTRL_POWERSTATE = OFF
> >> The TESLA Clocks and Power Domain settings are:
> >> 	TESLA_CM1 TESLA_CLKCTRL_MODULE_MODE = DISABLE
> >> 	TESLA_CM1 TESLA_CLKSTCTRL_CLKTRCTRL = HW_AUTO
> >> 	TESLA_PRM TESLA_PWRSTCTRL_POWERSTATE = OFF
> >>
> >> This patch fixes the low power OFF mode code so that the these
> >> registers are saved and restore across MPU OFF state.
> >>
> >> Also because of this limitation, MPU OFF alone is not targeted without
> >> device OFF to avoid IVAHD and TESLA execution impact
> >
> > I don't see where this restriction is implemented.
> >
> > And, can this be hooked into cluster PM notifiers.
> 
> Especially since this only effects a subset of revisions, installing the 
> notifier only on effected revisions also removes any overhead on working 
> revisions.

Where would you recommend adding the notifiers to? Just to the same file
or...? pm44xx.c?

-Tero