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

[Kevin Hilman]

Tero Kristo <t-kristo at ti.com> writes:

> 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?

Same file should be ok.

Kevin