Re: [PATCHSET] hotplug polling, take 5

[Jeff Garzik <jgarzik@pobox.com>]

Tejun Heo wrote:
> Hello, all.
> 
> This is the fifth take of hotplug polling patchset.  This take doesn't
> contain any real change than rebasing over the current upstream[U].
> PMP patchset will be posted soon on top of this patchset and I wanted
> to avoid confusion by posting patchsets in order.
> 
> As the name implies, this patchset implements hotplug by polling.
> hp-poll is used to
> 
> * Monitor ports EH gave up.  When EH gives up on a port, it freezes
>   the port to protect the rest of the system from it.  The user used
>   to have to issue manual scan to retry the port.  hp-poll can monitor
>   such port and retry it when hotplug event is detected.  This is also
>   used by PMP support.
> 
> * Support hotplug on controllers which can report hotplug conditions
>   but cannot raise interrupt.

Patchset seems sane.  I'll need to re-read patch #1 in depth, but I give 
everything a tentative ACK for now.

My biggest concern is power usage.  On laptops for example, the 99% 
common case is that the user will never hot[un]plug a drive, so we 
shouldn't waste power bothering with poking disabled ports.

	Jeff