Messages in this thread | | | Subject | Re: [PATCH 8/9] PM / Domains: Add support for multi PM domains per device to genpd | From | Jon Hunter <> | Date | Thu, 24 May 2018 10:36:34 +0100 |
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On 24/05/18 08:04, Ulf Hansson wrote:
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>> Any reason why we could not add a 'boolean' argument to the API to indicate >> whether the new device should be linked? I think that I prefer the API >> handles it, but I can see there could be instances where drivers may wish to >> handle it themselves. > > Coming back to this question. Both Tegra XUSB and Qcom Camera use > case, would benefit from doing the linking themselves, as it needs > different PM domains to be powered on depending on the current use > case - as to avoid wasting power. > > However, I can understand that you prefer some simplicity over > optimizations, as you told us. Then, does it mean that you are > insisting on extending the APIs with a boolean for linking, or are you > fine with the driver to call device_link_add()?
I am fine with the driver calling device_link_add(), but I just wonder if we will find a several drivers doing this and then we will end up doing this later anyway.
The current API is called ...
* genpd_dev_pm_attach_by_id() - Attach a device to one of its PM domain. * @dev: Device to attach. * @index: The index of the PM domain.
This naming and description is a bit misleading, because really it is not attaching the device that is passed, but creating a new device to attach a PM domain to. So we should consider renaming and changing the description and indicate that users need to link the device.
Finally, how is a PM domain attached via calling genpd_dev_pm_attach_by_id() detached?
Cheers Jon
-- nvpublic
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