[PATCH 2/4] ARM: tegra: pmc: add power on function for secondary CPUs

Stephen Warren swarren at wwwdotorg.org
Fri Feb 22 23:32:32 EST 2013


On 02/22/2013 07:38 PM, Joseph Lo wrote:
> On Fri, 2013-02-22 at 21:00 +0800, Peter De Schrijver wrote:
>> On Fri, Feb 22, 2013 at 07:44:49AM +0100, Joseph Lo wrote:
>>> Adding the power on function for secondary CPUs in PMC driver, this can
>>> help us to remove legacy powergate driver and add generic power domain
>>> support later.

>>> diff --git a/arch/arm/mach-tegra/pmc.c b/arch/arm/mach-tegra/pmc.c

>>> +static u8 tegra_cpu_domains[] = {
>>> +	0xFF,			/* not available for CPU0 */
>>
>> On Tegra114 we can also powergate CPU0, so this needs to be defined then.
>>
> No, DON'T DO THAT!!
> We don't allow any code to power gate CPU0 manually here or elsewhere.
> 
> The function here only for SMP and hotplug bring up for secondary CPU.

Doesn't Tegra114 have improved HW that does actually allow
power-gating/hot-unplugging/... CPU 0, even though older HW didn't?



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