Re: [RFC][PATCH] PM / Domains: Return -EPROBE_DEFER if we fail to init or turn-on domain

[Jon Hunter <jonathanh@nvidia.com>]

On 24/06/15 11:18, Ulf Hansson wrote:
> On 18 June 2015 at 19:52, Jon Hunter <jonathanh@nvidia.com> wrote:
>> When a device is probed, the function dev_pm_domain_attach() is called
>> to see if there is a power-domain that is associated with the device and
>> needs to be turned on. If dev_pm_domain_attach() does not return
>> -EPROBE_DEFER then the device will be probed.
>>
>> For devices using genpd, dev_pm_domain_attach() will call
>> genpd_dev_pm_attach(). If genpd_dev_pm_attach() does not find a power
>> domain associated with the device then it returns an error code not
>> equal to -EPROBE_DEFER to allow the device to be probed. However, if
>> genpd_dev_pm_attach() does find a power-domain that is associated with
>> the device, then it does not return -EPROBE_DEFER on failure and hence
>> the device will still be probed. Furthermore, genpd_dev_pm_attach() does
>> not check the error code returned by pm_genpd_poweron() to see if the
>> power-domain was turned on successfully.
>>
>> Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
> 
> This is a clear improvement for genpd and as a short-term solution I
> am fine with this!
> 
> The long term solution should be to implement the
> pm_domain->activate|dismiss() callbacks, but that requires a bigger
> effort.
> 
> Acked-by: Ulf Hansson <ulf.hansson@linaro.org>

Thanks Ulf.

Kevin, Rafael, are you ok with this?

Cheers
Jon

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