1. 15 Nov, 2008 6 commits
  2. 14 Nov, 2008 1 commit
    • Tejun Heo's avatar
      libata: improve phantom device detection · 6a6b97d3
      Tejun Heo authored
      
      
      Currently libata uses four methods to detect device presence.
      
      1. PHY status if available.
      2. TF register R/W test (only promotes presence, never demotes)
      3. device signature after reset
      4. IDENTIFY failure detection in SFF state machine
      
      Combination of the above works well in most cases but recently there
      have been a few reports where a phantom device causes unnecessary
      delay during probe.  In both cases, PHY status wasn't available.  In
      one case, it passed #2 and #3 and failed IDENTIFY with ATA_ERR which
      didn't qualify as #4.  The other failed #2 but as it passed #3 and #4,
      it still caused failure.
      
      In both cases, phantom device reported diagnostic failure, so these
      cases can be safely worked around by considering any !ATA_DRQ IDENTIFY
      failure as NODEV_HINT if diagnostic failure is set.
      
      Signed-off-by: default avatarTejun Heo <tj@kernel.org>
      Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
      6a6b97d3
  3. 13 Nov, 2008 33 commits