ENGR00215810-1 AHCI: sata drops to 1.5Gbps after suspend/resume several times

Add the AHCI platform suspend/resume function callback to
fix this issue.

Signed-off-by: Richard Zhu <Hong-Xing.Zhu@freescale.com>

diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index 6fef1fa75c549ea3a442f617693882313c826844..936babd0fb9e1f3f991cda6814beed6cacc484ca 100644 (file)
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -171,12 +171,78 @@ static int __devexit ahci_remove(struct platform_device *pdev)
        return 0;
 }
 
+#ifdef CONFIG_PM
+static int ahci_device_suspend(struct platform_device *pdev, pm_message_t msg)
+{
+       struct device *dev = &pdev->dev;
+       struct ahci_platform_data *pdata = dev_get_platdata(dev);
+       struct ata_host *host = dev_get_drvdata(dev);
+       struct ahci_host_priv *hpriv = host->private_data;
+       void __iomem *mmio = hpriv->mmio;
+       u32 ctl;
+       int rc;
+
+       if (hpriv->flags & AHCI_HFLAG_NO_SUSPEND) {
+               dev_err(dev, "firmware update required for suspend/resume\n");
+               return -EIO;
+       }
+
+       /*
+       * AHCI spec rev1.1 section 8.3.3:
+       * Software must disable interrupts prior to requesting a
+       * transition of the HBA to D3 state.
+       */
+       ctl = readl(mmio + HOST_CTL);
+       ctl &= ~HOST_IRQ_EN;
+       writel(ctl, mmio + HOST_CTL);
+       readl(mmio + HOST_CTL); /*  flush */
+
+       rc = ata_host_suspend(host, msg);
+       if (rc)
+               return rc;
+
+       if (pdata && pdata->suspend)
+               return pdata->suspend(dev);
+       return 0;
+}
+
+static int ahci_device_resume(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct ahci_platform_data *pdata = dev_get_platdata(dev);
+       struct ata_host *host = dev_get_drvdata(dev);
+       int rc;
+
+       if (pdata && pdata->resume) {
+               rc = pdata->resume(dev);
+               if (rc)
+                       return rc;
+       }
+
+       if (dev->power.power_state.event == PM_EVENT_SUSPEND) {
+               rc = ahci_reset_controller(host);
+               if (rc)
+                       return rc;
+
+               ahci_init_controller(host);
+       }
+
+       ata_host_resume(host);
+
+       return 0;
+}
+#endif /* CONFIG_PM */
+
 static struct platform_driver ahci_driver = {
        .remove = __devexit_p(ahci_remove),
        .driver = {
                .name = "ahci",
                .owner = THIS_MODULE,
        },
+#ifdef CONFIG_PM
+       .suspend        = ahci_device_suspend,
+       .resume         = ahci_device_resume,
+#endif
 };
 
 static int __init ahci_init(void)