On Mon, Jun 02, 2008 at 02:40:51PM -0400, Jeff Garzik wrote:
> A better patch would enable the _possibility_ of power savings on
> non-AHCI chips, and not add a one-off AHCI-specific user interface that
> must be supported for years to come.
So how about somethig like the following, where the module parameter
just gets moved to libata rather than ahci? Entirely untested, I don't
have ahci on this machine.
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 97f83fb..5913ebb 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -56,6 +56,7 @@ MODULE_PARM_DESC(skip_host_reset, "skip global host reset (0=don't skip, 1=skip)
static int ahci_enable_alpm(struct ata_port *ap,
enum link_pm policy);
static void ahci_disable_alpm(struct ata_port *ap);
+static int ahci_is_hotplug_capable(struct ata_port *ap);
enum {
AHCI_PCI_BAR = 5,
@@ -166,6 +167,8 @@ enum {
PORT_CMD_ASP = (1 << 27), /* Aggressive Slumber/Partial */
PORT_CMD_ALPE = (1 << 26), /* Aggressive Link PM enable */
PORT_CMD_ATAPI = (1 << 24), /* Device is ATAPI */
+ PORT_CMD_ESP = (1 << 21), /* External SATA Port */
+ PORT_CMD_HPCP = (1 << 18), /* port is hot plug capable */
PORT_CMD_PMP = (1 << 17), /* PMP attached */
PORT_CMD_LIST_ON = (1 << 15), /* cmd list DMA engine running */
PORT_CMD_FIS_ON = (1 << 14), /* FIS DMA engine running */
@@ -1900,6 +1903,15 @@ static int ahci_pci_device_resume(struct pci_dev *pdev)
}
#endif
+static int ahci_is_hotplug_capable(struct ata_port *ap)
+{
+ void __iomem *port_mmio = ahci_port_base(ap);
+ u8 cmd;
+
+ cmd = readl(port_mmio + PORT_CMD);
+ return ((cmd & PORT_CMD_HPCP) || (cmd & PORT_CMD_ESP));
+}
+
static int ahci_port_start(struct ata_port *ap)
{
struct device *dev = ap->host->dev;
@@ -1951,6 +1963,9 @@ static int ahci_port_start(struct ata_port *ap)
ap->private_data = pp;
+ /* set some flags based on port capabilities */
+ if (!ahci_is_hotplug_capable(ap))
+ ap->flags |= ATA_FLAG_NO_HOTPLUG;
/* engage engines, captain */
return ahci_port_resume(ap);
}
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 3c89f20..209efe5 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -157,11 +157,28 @@ int libata_allow_tpm = 0;
module_param_named(allow_tpm, libata_allow_tpm, int, 0444);
MODULE_PARM_DESC(allow_tpm, "Permit the use of TPM commands");
+static int sata_power_save = 1;
+module_param_named(sata_power_save, sata_power_save, int, 0644);
+MODULE_PARM_DESC(sata_power_save, "Power off unused ports (0=don't power off, 1=power off)");
+
MODULE_AUTHOR("Jeff Garzik");
MODULE_DESCRIPTION("Library module for ATA devices");
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
@@ -2678,6 +2695,7 @@ void ata_port_disable(struct ata_port *ap)
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);
}
/**
@@ -5614,6 +5632,8 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
if (ap->ops->error_handler) {
struct ata_eh_info *ehi = &ap->link.eh_info;
unsigned long flags;
+ int device_attached = 0;
+ struct ata_device *dev;
ata_port_probe(ap);
@@ -5632,6 +5652,14 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
/* wait for EH to finish */
ata_port_wait_eh(ap);
+ ata_link_for_each_dev(dev, &ap->link)
+ if (ata_dev_enabled(dev))
+ device_attached++;
+ if (!device_attached && sata_power_save &&
+ (ap->flags & ATA_FLAG_NO_HOTPLUG)) {
+ /* no device present, disable port */
+ ata_port_disable(ap);
+ }
} else {
DPRINTK("ata%u: bus probe begin\n", ap->print_id);
rc = ata_bus_probe(ap);
--
Matthew Garrett | mjg59@xxxxxxxxxxxxx
--
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
