Re: [PATCH 01/10] libata: power down controller only on PMSG_SUSPEND

[Jeff Garzik <jgarzik@pobox.com>]

Tejun Heo wrote:
> The controller only needs to be powered down on PMSG_SUSPEND.  Skip
> powering down for all other messages.  This makes disk suspend prep
> cycle more efficient and helps controllers which have problems waking
> up from D3hot without intervening power removal.
> 
> Signed-off-by: Tejun Heo <htejun@gmail.com>
> 
> ---
> 
>  drivers/scsi/libata-core.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> 85016ad86323924d10dc99ac9d7e9e5c0b967b8e
> diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
> index 9a3bd15..51d3b4b 100644
> --- a/drivers/scsi/libata-core.c
> +++ b/drivers/scsi/libata-core.c
> @@ -5661,7 +5661,10 @@ int ata_pci_device_suspend(struct pci_de
>  {
>  	pci_save_state(pdev);
>  	pci_disable_device(pdev);
> -	pci_set_power_state(pdev, PCI_D3hot);
> +
> +	if (state.event == PM_EVENT_SUSPEND)
> +		pci_set_power_state(pdev, PCI_D3hot);

If this change makes sense for the D0->D3 transition, surely it would 
make sense to cover the other operations (save-state, disable) as well?

	Jeff