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

[Shilimkar, Santosh]

On Thu, May 17, 2012 at 10:15 PM, Kevin Hilman <khilman at ti.com> wrote:
> "Shilimkar, Santosh" <santosh.shilimkar at ti.com> writes:
>
>> On Thu, May 17, 2012 at 4:35 AM, Kevin Hilman <khilman at ti.com> 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.
>>>
>> It's handled and the patch is in mainline for some time.
>> We de-scoped MPU OFF from OMAP4430 devices in SW and
>> hardware team de-scoped it in hardware from OMAP4460 onwards.
>> Deepest state on MPUSS cluster is OSWR.
>
> The question was about the changelog.
>
> The changelog makes it sound like the restriction is part of the patch,
> but it is not.  Please update the changlog to clarify that, ideally
> adding a reference to the commit you mentioned.
>
Agree.