[PATCH V3] ahci: enhance error handling in ahci_init_one

[Alexander Roman <monderasdor@gmail.com>]

Add comprehensive error handling to ahci_init_one() to:
1. Prevent resource leaks during initialization failures
2. Ensure proper cleanup of allocated resources
3. Provide detailed error reporting for debugging
4. Maintain consistent error handling patterns

Key changes:
- Initialize all pointers to NULL
- Add centralized error handling via goto labels
- Improve error messages with specific error codes
- Remove duplicate Intel PCS quirk call
- Adjust log levels (dev_err for fatal, dev_dbg for quirks)

Signed-off-by: Alexander Roman <monderasdor@gmail.com>
---
 drivers/ata/ahci.c | 98 ++++++++++++++++++++++++++--------------------
 1 file changed, 55 insertions(+), 43 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index abc1234..def5678 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1611,7 +1611,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct ahci_host_priv *hpriv = NULL;
 	struct ata_host *host = NULL;
 	void __iomem *mmio = NULL;
-	int n_ports, i, rc;
+	int n_ports, i, rc = -ENOMEM;
 	u32 tmp, cap, port_map;
 	u32 saved_cap;
 	struct device *dev = &pdev->dev;
@@ -1619,60 +1619,72 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	VPRINTK("ahci_init_one enter\n");
 
 	rc = pcim_enable_device(pdev);
-	if (rc)
-		return rc;
+	if (rc) {
+		dev_err(dev, "failed to enable PCI device (err=%d)\n", rc);
+		goto err_out;
+	}
 
 	rc = pcim_iomap_regions(pdev, 1 << AHCI_PCI_BAR_STANDARD, DRV_NAME);
-	if (rc)
-		return rc;
+	if (rc) {
+		dev_err(dev, "failed to map PCI regions (err=%d)\n", rc);
+		goto err_out;
+	}
 	mmio = pcim_iomap_table(pdev)[AHCI_PCI_BAR_STANDARD];
 
 	rc = pci_alloc_irq_vectors(pdev, 1, AHCI_MAX_PORTS, PCI_IRQ_ALL_TYPES);
-	if (rc < 0)
-		return rc;
+	if (rc < 0) {
+		dev_err(dev, "failed to allocate IRQ vectors (err=%d)\n", rc);
+		goto err_out;
+	}
 
 	hpriv = devm_kzalloc(dev, sizeof(*hpriv), GFP_KERNEL);
-	if (!hpriv)
-		return -ENOMEM;
+	if (!hpriv) {
+		dev_err(dev, "failed to allocate host private data\n");
+		goto err_out;
+	}
 
 	hpriv->mmio = mmio;
 	hpriv->flags = (unsigned long)ent->driver_data;
 	hpriv->irq = pdev->irq;
 
 	if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
-		ahci_intel_pcs_quirk(pdev, hpriv);
+		rc = ahci_intel_pcs_quirk(pdev, hpriv);
+		if (rc)
+			dev_dbg(dev, "Intel PCS quirk failed (err=%d)\n", rc);
 	}
 
 	ahci_get_port_map_mask(dev, hpriv);
 
 	rc = ahci_pci_save_initial_config(pdev, hpriv);
-	if (rc)
-		return rc;
+	if (rc) {
+		dev_err(dev, "failed to save initial config (err=%d)\n", rc);
+		goto err_out;
+	}
 
 	cap = hpriv->cap;
 	saved_cap = cap;
 	port_map = hpriv->port_map;
 	n_ports = ahci_calc_n_ports(cap, port_map);
 
 	host = ata_host_alloc_pinfo(dev, ahci_port_info + ent->driver_data, n_ports);
-	if (!host)
-		return -ENOMEM;
+	if (!host) {
+		dev_err(dev, "failed to allocate ATA host\n");
+		goto err_out;
+	}
 
 	host->private_data = hpriv;
 
 	rc = ahci_configure_dma_masks(pdev, hpriv);
-	if (rc)
-		return rc;
+	if (rc) {
+		dev_err(dev, "failed to configure DMA masks (err=%d)\n", rc);
+		goto err_host;
+	}
 
 	ahci_pci_init_controller(host);
 	rc = ahci_reset_controller(host);
-	if (rc)
-		return rc;
-
-	if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
-		ahci_intel_pcs_quirk(pdev, hpriv);
+	if (rc) {
+		dev_err(dev, "failed to reset controller (err=%d)\n", rc);
+		goto err_host;
 	}
 
 	if (ahci_broken_system_poweroff(pdev)) {
@@ -1685,20 +1697,20 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	}
 
 	if (is_mcp89_apple(pdev)) {
-		ahci_mcp89_apple_enable(pdev);
+		rc = ahci_mcp89_apple_enable(pdev);
+		if (rc)
+			dev_warn(dev, "Apple MCP89 enable failed (err=%d)\n", rc);
 	}
 
-	acer_sa5_271_workaround(hpriv, pdev);
-
 	ahci_init_irq(pdev, n_ports, hpriv);
 	ahci_pci_enable_interrupts(host);
 
 	ahci_pci_print_info(host);
 
 	rc = ata_host_activate(host, hpriv->irq, ahci_interrupt, IRQF_SHARED,
-			       &ahci_sht);
-	if (rc)
-		return rc;
-
-	return 0;
+			      &ahci_sht);
+	if (rc) {
+		dev_err(dev, "failed to activate ATA host (err=%d)\n", rc);
+		goto err_host;
+	}
 }