[PATCHSET 06/11] prep for hotplug support, take 2

[Tejun Heo <htejun@gmail.com>]

Bang-Ga.

This is part of patchset series described in [T].

This is the second take of prep-for-hotplug-support patchset.  Changes
from the last take[L] are

* dev->flags is used for warm plug and synchronized with host_set
  lock.  ata_dev_init() is updated to clear non-persistent part of
  dev->flags while holding host_set lock.

* ap->orig_sata_spd_limit renamed to ap->hw_sata_spd_limit.

* sata_phy_debounce() implemented.  This function will be called
  before performing EH resets to settle devices instead of blind
  delay.  sata_phy_debounce() is superset of the wait used in
  sata_phy_resume() and sata_phy_resume() is converted to use it.

* TF access is made optional.  All probing (including boot probing)
  will be done via hotplug and hotplug probing is implemented such
  that ->tf_read/write() isn't necessary, so now drivers like
  sata_sil24 don't have to fake TF access.  As ->check_[alt]status()
  was embedded too deep, ata_noop_check_status() is added instead of
  making those methods optional.  In the long term, those low level
  methods should be separated from highlevel ops somehow.

* ops->prereset() added.  This function is the counterpart of
  postreset() and called before a series of resets.  This is quite
  similar to ->probe_init() except that it's called for all resets.
  prereset() can determine things like whether it's prepping for boot
  probing or not, and which reset will be performed by testing
  ap->flags and ehi.

* Followup-softreset handling implemented.

* hotplug will completely replace ->probe_init/reset().

This patchset is against

  upstream (acc696d93dcf993dec123d69d599979e1456ffec)
  + [1] prep-for-new-EH patchset
  + [2] new-EH-framework patchset, take 3
  + [3] new-EH-implementation patchset, take 3
  + [4] merge-irq-pio patchset
  + [5] add-NCQ-support patchset, take 3

--
tejun

[T] http://article.gmane.org/gmane.linux.ide/9957
[L] http://article.gmane.org/gmane.linux.ide/9579
[1] http://article.gmane.org/gmane.linux.ide/9959
[2] http://article.gmane.org/gmane.linux.ide/9984
[3] http://article.gmane.org/gmane.linux.ide/9995
[4] http://article.gmane.org/gmane.linux.ide/10005
[5] http://article.gmane.org/gmane.linux.ide/10011