AMBA: PM domains when !CONFIG_PM
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 ?
Signature · 2 lines
Regards, Sudeep
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Quoted 21 lines · Ulf Hansson
On 16 June 2016 at 13:19, Sudeep Holla <[email protected] <mailto:[email protected]>> 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.cThe problem is when we disable
CONFIG_PM,dev_pm_domain_attachreturns-ENODEVirrespective of whether a DT node has a PM domain in it or not. Ifdev_pm_domain_attachreturns 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 ?
Quoted 6 lines
The solution TEGRA picked for a kind of similar issue was to enable
CONFIG_PMfor 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.
Signature · 2 lines
Regards, Sudeep