libata: handle pci_enable_device() failure while resuming

Handle pci_enable_device() failure while resuming.  This patch kills
the "ignoring return value of 'pci_enable_device'" warning message and
propagates __must_check through ata_pci_device_do_resume().

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index ca53d5a..03b7a005 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1397,7 +1397,9 @@
 	void __iomem *mmio = host->mmio_base;
 	int rc;
 
-	ata_pci_device_do_resume(pdev);
+	rc = ata_pci_device_do_resume(pdev);
+	if (rc)
+		return rc;
 
 	if (pdev->dev.power.power_state.event == PM_EVENT_SUSPEND) {
 		rc = ahci_reset_controller(mmio, pdev);
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index a03019c..89f3cf5 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -6196,12 +6196,22 @@
 	}
 }
 
-void ata_pci_device_do_resume(struct pci_dev *pdev)
+int ata_pci_device_do_resume(struct pci_dev *pdev)
 {
+	int rc;
+
 	pci_set_power_state(pdev, PCI_D0);
 	pci_restore_state(pdev);
-	pci_enable_device(pdev);
+
+	rc = pci_enable_device(pdev);
+	if (rc) {
+		dev_printk(KERN_ERR, &pdev->dev,
+			   "failed to enable device after resume (%d)\n", rc);
+		return rc;
+	}
+
 	pci_set_master(pdev);
+	return 0;
 }
 
 int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
@@ -6221,10 +6231,12 @@
 int ata_pci_device_resume(struct pci_dev *pdev)
 {
 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	int rc;
 
-	ata_pci_device_do_resume(pdev);
-	ata_host_resume(host);
-	return 0;
+	rc = ata_pci_device_do_resume(pdev);
+	if (rc == 0)
+		ata_host_resume(host);
+	return rc;
 }
 #endif /* CONFIG_PCI */
 
diff --git a/drivers/ata/sata_sil.c b/drivers/ata/sata_sil.c
index d27ab31..1f3fdcf 100644
--- a/drivers/ata/sata_sil.c
+++ b/drivers/ata/sata_sil.c
@@ -710,8 +710,12 @@
 static int sil_pci_device_resume(struct pci_dev *pdev)
 {
 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
+	int rc;
 
-	ata_pci_device_do_resume(pdev);
+	rc = ata_pci_device_do_resume(pdev);
+	if (rc)
+		return rc;
+
 	sil_init_controller(pdev, host->n_ports, host->ports[0]->flags,
 			    host->mmio_base);
 	ata_host_resume(host);
diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
index 5aa288d..da982ed 100644
--- a/drivers/ata/sata_sil24.c
+++ b/drivers/ata/sata_sil24.c
@@ -1200,8 +1200,11 @@
 {
 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
 	struct sil24_host_priv *hpriv = host->private_data;
+	int rc;
 
-	ata_pci_device_do_resume(pdev);
+	rc = ata_pci_device_do_resume(pdev);
+	if (rc)
+		return rc;
 
 	if (pdev->dev.power.power_state.event == PM_EVENT_SUSPEND)
 		writel(HOST_CTRL_GLOBAL_RST, hpriv->host_base + HOST_CTRL);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index dab4dc5..a8ecaaa 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -716,7 +716,7 @@
 			     unsigned int n_ports);
 extern void ata_pci_remove_one (struct pci_dev *pdev);
 extern void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg);
-extern void ata_pci_device_do_resume(struct pci_dev *pdev);
+extern int __must_check ata_pci_device_do_resume(struct pci_dev *pdev);
 extern int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg);
 extern int ata_pci_device_resume(struct pci_dev *pdev);
 extern int ata_pci_clear_simplex(struct pci_dev *pdev);