libata: issue DIPM enable commands with LPM state updated
authorTejun Heo <tj@kernel.org>
Thu, 9 Dec 2010 15:13:15 +0000 (16:13 +0100)
committerJeff Garzik <jgarzik@redhat.com>
Fri, 24 Dec 2010 18:34:34 +0000 (13:34 -0500)
commite5005b15c91f3362036067bde5210d5c78af2f0d
treecbddea07bc4b27921f40a7cc0c0a687d7239041e
parentf08dc1ac6b15c681f4643d8da1700e06c3855608
libata: issue DIPM enable commands with LPM state updated

Low level drivers may behave differently depending on the current
link->lpm_policy.  During ata_eh_set_lpm(), DIPM enable commands are
issued after the successful completion of ap->ops->set_lpm(), which
means that the controller is already in the target state.  This causes
DIPM enable commands to be processed with mismatching controller power
state and link->lpm_policy value.

In ahci, link->lpm_policy is used to ignore certain PHY events if LPM
is enabled; however, as DIPM commands are issued with stale
link->lpm_policy, they sometimes end up triggering these conditions
and get aborted leading to LPM configuration failure.

Fix it by updating link->lpm_policy before issuing DIPM enable
commands.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Kyle McMartin <kyle@mcmartin.ca>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
drivers/ata/libata-eh.c