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Date: Thu, 12 Mar 2015 21:11:52 +0800
From: Vince Hsu <vinceh@nvidia.com>
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To: Thierry Reding <thierry.reding@gmail.com>
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Subject: Re: [PATCH v2 17/17] soc/tegra: remove lagacy powergate APIs
References: <1426162518-7405-1-git-send-email-vinceh@nvidia.com> <1426162518-7405-18-git-send-email-vinceh@nvidia.com> <20150312124501.GA632@ulmo>
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Hi,

On 03/12/2015 08:45 PM, Thierry Reding wrote:
> * PGP Signed by an unknown key
>
> On Thu, Mar 12, 2015 at 08:15:18PM +0800, Vince Hsu wrote:
>> We switch to generic power domain now. So remove the legacy functions.
>>
>> Signed-off-by: Vince Hsu <vinceh@nvidia.com>
>> ---
>>   drivers/soc/tegra/pmc.c | 68 -------------------------------------------------
>>   include/soc/tegra/pmc.h | 22 ----------------
>>   2 files changed, 90 deletions(-)
> I don't think we can do this. What if somebody updates their kernel but
> not the DTB? In that case they'll end up with drivers that don't enable
> power partitions but at the same time the powergate driver won't enable
> them either because it is missing the corresponding nodes in the DTB.
You're right.

>
> What we'll have to do is probably keep the code that enables the power
> partitions and make it conditional on the power domains somehow. Is
> there a way to determine at runtime whether a device has been attached
> to a power domain?
>
Yes, we can check if a power domain is bound to the GPD by DT in the 
legacy powergate code.

Thanks,
Vince