Re: [PATCH #upstream-fixes] libata: issue DIPM enable commands with LPM state updated

[Jeff Garzik <jeff@garzik.org>]

On 12/09/2010 10:13 AM, Tejun Heo wrote:
> 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
> ---
>   drivers/ata/libata-eh.c |   17 ++++++++++++++---
>   1 file changed, 14 insertions(+), 3 deletions(-)

applied