1 files changed, 33 insertions, 5 deletions

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 738fb22978dd..b14dccda0154 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -609,7 +609,7 @@ static int marvell_enable = 1;
 module_param(marvell_enable, int, 0644);
 MODULE_PARM_DESC(marvell_enable, "Marvell SATA via AHCI (1 = enabled)");
 
-static int mobile_lpm_policy = CONFIG_SATA_MOBILE_LPM_POLICY;
+static int mobile_lpm_policy = -1;
 module_param(mobile_lpm_policy, int, 0644);
 MODULE_PARM_DESC(mobile_lpm_policy, "Default LPM policy for mobile chipsets");
 
@@ -1550,6 +1550,37 @@ static int ahci_init_msi(struct pci_dev *pdev, unsigned int n_ports,
         return pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSIX);
 }
 
+static void ahci_update_initial_lpm_policy(struct ata_port *ap,
+                                           struct ahci_host_priv *hpriv)
+{
+        int policy = CONFIG_SATA_MOBILE_LPM_POLICY;
+
+
+        /* Ignore processing for non mobile platforms */
+        if (!(hpriv->flags & AHCI_HFLAG_IS_MOBILE))
+                return;
+
+        /* user modified policy via module param */
+        if (mobile_lpm_policy != -1) {
+                policy = mobile_lpm_policy;
+                goto update_policy;
+        }
+
+#ifdef CONFIG_ACPI
+        if (policy > ATA_LPM_MED_POWER &&
+            (acpi_gbl_FADT.flags & ACPI_FADT_LOW_POWER_S0)) {
+                if (hpriv->cap & HOST_CAP_PART)
+                        policy = ATA_LPM_MIN_POWER_WITH_PARTIAL;
+                else if (hpriv->cap & HOST_CAP_SSC)
+                        policy = ATA_LPM_MIN_POWER;
+        }
+#endif
+
+update_policy:
+        if (policy >= ATA_LPM_UNKNOWN && policy <= ATA_LPM_MIN_POWER)
+                ap->target_lpm_policy = policy;
+}
+
 static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
         unsigned int board_id = ent->driver_data;
@@ -1747,10 +1778,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
                 if (ap->flags & ATA_FLAG_EM)
                         ap->em_message_type = hpriv->em_msg_type;
 
-                if ((hpriv->flags & AHCI_HFLAG_IS_MOBILE) &&
-                    mobile_lpm_policy >= ATA_LPM_UNKNOWN &&
-                    mobile_lpm_policy <= ATA_LPM_MIN_POWER)
-                        ap->target_lpm_policy = mobile_lpm_policy;
+                ahci_update_initial_lpm_policy(ap, hpriv);
 
                 /* disabled/not-implemented port */
                 if (!(hpriv->port_map & (1 << i)))