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

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On 05/16/2012 04:05 PM, Kevin Hilman wrote:
Tero Kristo<t-kristo@xxxxxx>  writes:

From: Santosh Shilimkar<santosh.shilimkar@xxxxxx>

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.

Kevin
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