tree 6bf8e7f5dad9917e07edf126e24a40f101f6a496
parent 4c2a8c40d877effc25774f00406a4a7df1967102
author Stephen M. Cameron <scameron@beardog.cce.hp.com> 1276714300 -0500
committer James Bottomley <James.Bottomley@suse.de> 1280250120 -0500

[SCSI] hpsa: Fix hard reset code.

Smart Array controllers newer than the P600 do not honor the
PCI power state method of resetting the controllers.  Instead,
in these cases we can get them to reset via the "doorbell" register.

This escaped notice until we began using "performant" mode because
the fact that the controllers did not reset did not normally
impede subsequent operation, and so things generally appeared to
"work".  Once the performant mode code was added, if the controller
does not reset, it remains in performant mode.  The code immediately
after the reset presumes the controller is in "simple" mode
(which previously, it had remained in simple mode the whole time).
If the controller remains in performant mode any code which presumes
it is in simple mode will not work.  So the reset needs to be fixed.

Unfortunately there are some controllers which cannot be reset by
either method. (eg. p800).  We detect these cases by noticing that
the controller seems to remain in performant mode even after a
reset has been attempted.  In those case, we proceed anyway,
as if the reset has happened (and skip the step of waiting for
the controller to become ready -- which is expecting it to be in
"simple" mode.)  To sum up, we try to do a better job of resetting
the controller if "reset_devices" is set, and if it doesn't work,
we print a message and try to continue anyway.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>