Re: [RFC 00/15] Resource tracking/allocation framework

From: Russell King - ARM Linux
Date: Wed Dec 10 2014 - 11:16:44 EST

On Wed, Dec 10, 2014 at 04:48:18PM +0100, Andrzej Hajda wrote:
> 3. There are drivers which can work without specific resource, but if
> the resource becomes available/unavailable it can do some additional stuff.
> An example of such driver is DRM driver (more precisely drm_connector) -
> it can start without attached drm_panel, but if the panel becomes available it
> can react by generating HPD event and start using it.

Bad example, and actually incorrect. DRM connectors are referenced in
userspace by an IDR number, which can be re-used in the case of a
connector appearing, disappearing, and then a different connector

DRM really is *not* safe to hotplug like this: DRM is more a card-level
thing, which is why we have the component helpers - which allow us to
merge several devices into one logical card-like device in a generic

DRM needs a stable picture of the CRTCs, encoders and connectors, which
should _never_ change during the lifetime of the DRM device. Devices
attached to connectors can be hotplugged, but that's about the limit of
hot-plugging in DRM.

FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up
according to
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