From: sudeep.holla@arm•com (Sudeep Holla)
To: linux-arm-kernel@lists•infradead.org
Subject: [QUERY] AMBA: PM domains when !CONFIG_PM
Date: Thu, 16 Jun 2016 13:47:31 +0100 [thread overview]
Message-ID: <57629FE3.8050303@arm.com> (raw)
In-Reply-To: <CAPDyKFoV5Y1mHuDZmWgynCicux2deV89npp-siTQDJr0uZFwcg@mail.gmail.com>
On 16/06/16 13:33, Ulf Hansson wrote:
>
>
> On 16 June 2016 at 13:19, Sudeep Holla <sudeep.holla@arm•com
> <mailto:sudeep.holla@arm•com>> wrote:
>
> Hi Ulf, Kevin,
>
> I have a situation where we need to enable the power domain to access an
> AMBA device. This is all fine with patches from Ulf and Marek in
> amba/bus.c
>
> The problem is when we disable CONFIG_PM, dev_pm_domain_attach
> returns -ENODEV irrespective of whether a DT node has a PM domain
> in it or not. If dev_pm_domain_attach returns anything other than
> -EPROBE_DEFER, we ignore the error and proceed to access the device
> which will explode.
>
> Basically, we need a way to prevent addition of that amba device if DT
> node has PD specified but CONFIG_PM=n. Any thoughts ?
>
>
> The solution TEGRA picked for a kind of similar issue was to enable
> CONFIG_PM for a family of SoCs.
>
> I assume this would be applicable here as well, or are you saying this
> platform actually is able to work *without* PM support?
>
I agree, but if someone tries to boot with !CONFIG_PM, it just hangs
without a clue, hence I raised this query. I am fine by forcing it to be
ON always, but just wanted to check if this is something serious that it
needs to be addressed.
Thanks for the quick response.
--
Regards,
Sudeep
prev parent reply other threads:[~2016-06-16 12:47 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-16 11:19 [QUERY] AMBA: PM domains when !CONFIG_PM Sudeep Holla
[not found] ` <CAPDyKFoV5Y1mHuDZmWgynCicux2deV89npp-siTQDJr0uZFwcg@mail.gmail.com>
2016-06-16 12:47 ` Sudeep Holla [this message]
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