kristen.c.accardi@xxxxxxxxx wrote:
This patch expands the definition of link power management to
include the notion of simply powering the entire port off.
We add a new valid value for link_power_management_policy:
power_off: phy is not on at all.
min_power: driver uses minimum possible power. hotplug
may or may not be available.
medium_power: best power/performance tradeoff. hotplug
may or may not be available
max_performance: max performance without regard to power
hot plug is available.
Additionally - this patch modifies the libata-core to
power off the port automatically at init time if the
driver marks the port as not hotpluggable.
The user may not power off a port if it is occupied.
If the port is powered off, and a new drive is plugged
in, the drive will not be detected until the port is
powered back up by setting the link_power_management_policy
to "max_performance".
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@xxxxxxxxx>
---
drivers/ata/libata-core.c | 58 +++++++++++++++++++++++++++++++++++++++++++++-
drivers/ata/libata-scsi.c | 1
include/linux/libata.h | 2 +
3 files changed, 60 insertions(+), 1 deletion(-)
Index: linux-ahci-phy/drivers/ata/libata-core.c
===================================================================
--- linux-ahci-phy.orig/drivers/ata/libata-core.c 2008-06-27 13:32:51.000000000 -0700
+++ linux-ahci-phy/drivers/ata/libata-core.c 2008-07-01 16:33:00.000000000 -0700
@@ -162,6 +162,19 @@ MODULE_DESCRIPTION("Library module for A
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
+static void ata_phy_offline(struct ata_link *link)
+{
+ u32 scontrol;
+ int rc;
+
+ /* set DET to 4 */
+ rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
+ if (rc)
+ return;
+ scontrol &= ~0xf;
+ scontrol |= (1 << 2);
+ sata_scr_write(link, SCR_CONTROL, scontrol);
+}
/**
* ata_force_cbl - force cable type according to libata.force
@@ -953,6 +966,7 @@ static int ata_dev_set_dipm(struct ata_d
* disallow all transitions which effectively
* disable DIPM anyway.
*/
+ default:
break;
}
@@ -980,6 +994,22 @@ void ata_dev_enable_pm(struct ata_device
int rc = 0;
struct ata_port *ap = dev->link->ap;
+ /*
+ * if we don't have a device attached, all we can
+ * do is power off
+ */
+ if (!ata_dev_enabled(dev) && policy == POWER_OFF) {
+ ap->flags |= ATA_FLAG_NO_HOTPLUG;
+ ata_phy_offline(&ap->link);
+ goto enable_pm_out;
+ }
+
+ /*
+ * if there's no device attached, we are done
+ */
+ if (!ata_dev_enabled(dev))
+ return;
+
/* set HIPM first, then DIPM */
if (ap->ops->enable_pm)
rc = ap->ops->enable_pm(ap, policy);
@@ -1020,10 +1050,24 @@ static void ata_dev_disable_pm(struct at
void ata_lpm_schedule(struct ata_port *ap, enum link_pm policy)
{
- ap->pm_policy = policy;
ap->link.eh_info.action |= ATA_EH_LPM;
+
+ /*
+ * if we are coming from a state of OFF to ON, we need
+ * to reset the link and scan for devices in case someone
+ * plugged something in while we were off.
+ * Clear the NO_HOTPLUG flag because we are leaving the
+ * phy on now.
+ */
+ if (ap->pm_policy == POWER_OFF && policy != POWER_OFF) {
+ ap->flags &= ~ATA_FLAG_NO_HOTPLUG;
+ ap->link.eh_info.probe_mask |= ATA_ALL_DEVICES;
+ ap->link.eh_info.flags |= ATA_EH_RESET;
+ }
ap->link.eh_info.flags |= ATA_EHI_NO_AUTOPSY;
+ ap->pm_policy = policy;
ata_port_schedule_eh(ap);
+ ata_port_wait_eh(ap);
}
#ifdef CONFIG_PM
just a question... why wait for EH?
@@ -2678,6 +2722,7 @@ void ata_port_disable(struct ata_port *a
ap->link.device[0].class = ATA_DEV_NONE;
ap->link.device[1].class = ATA_DEV_NONE;
ap->flags |= ATA_FLAG_DISABLED;
+ ata_phy_offline(&ap->link);
}
/**
do we really want to unconditionally assume SATA here?
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
