libata hotplug question

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

So pata_macio is starting to look good, it even suspends and resumes on
a couple of test laptops, now is time to sort out the last piece of the
puzzle, which is the hotplug media-bay.

The old code use to call directly into drivers/ide ide_port_scan()
etc... from within the mediabay driver. Pretty filthy.

I'm changing that to something that's even simpler: the macio_driver
gets a new callback for plug/unplug events from the bay, so it will be
easy to keep the old driver do whatever drivers/ide cruft it wants
locally and do something different in libata.

Now, for libata, I haven't totally figured out what to do though.

It seems like when the state "changes", I can do something like ahci and
call ata_ehi_hotplugged() followed by something like ata_port_freeze()
to kick the EH... at least that's my rough understanding.

But I don't quite get how to inform libata that the part has or has not
something plugged in it. I thought about playing with the probe_mask but
it looks like ata_eh_link_autopsy() will reset that since I'm PATA, not
SATA and thus have no sata_scr_read()...

Any suggestion here ?

Cheers,
Ben.