[PATCH] ata: ahci: preserve preset port masks

[zhoumin <teczm@foxmail.com>]

ahci_get_port_mask() returns zero for absent or unmatched parameters,
overwriting the mask set by the Marvell PATA quirk.

Update the mask in place only when parsing a global value or a matching
device entry. Preserve existing numeric parsing and override behavior.

Fixes: 70c1595c181c ("ata: ahci: Allow ignoring the external/hotplug capability of ports")
Signed-off-by: zhoumin <teczm@foxmail.com>
---
 drivers/ata/ahci.c | 21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 9b8c0935001c..324e4918a055 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1654,22 +1654,21 @@ static u32 ahci_port_mask(struct device *dev, char *mask_s)
 	return mask;
 }
 
-static u32 ahci_get_port_mask(struct device *dev, char *mask_p)
+static void ahci_get_port_mask(struct device *dev, char *mask_p, u32 *mask)
 {
 	char *param, *end, *str, *mask_s;
 	char *name;
-	u32 mask = 0;
 
 	if (!mask_p || !strlen(mask_p))
-		return 0;
+		return;
 
 	str = kstrdup(mask_p, GFP_KERNEL);
 	if (!str)
-		return 0;
+		return;
 
 	/* Handle single mask case */
 	if (!strchr(str, '=')) {
-		mask = ahci_port_mask(dev, str);
+		*mask = ahci_port_mask(dev, str);
 		goto free;
 	}
 
@@ -1704,13 +1703,11 @@ static u32 ahci_get_port_mask(struct device *dev, char *mask_p)
 			param++;
 		}
 
-		mask = ahci_port_mask(dev, mask_s);
+		*mask = ahci_port_mask(dev, mask_s);
 	}
 
 free:
 	kfree(str);
-
-	return mask;
 }
 
 static void ahci_pci_save_initial_config(struct pci_dev *pdev,
@@ -1736,10 +1733,10 @@ static void ahci_pci_save_initial_config(struct pci_dev *pdev,
 	}
 
 	/* Handle port map masks passed as module parameter. */
-	hpriv->mask_port_map =
-		ahci_get_port_mask(&pdev->dev, ahci_mask_port_map);
-	hpriv->mask_port_ext =
-		ahci_get_port_mask(&pdev->dev, ahci_mask_port_ext);
+	ahci_get_port_mask(&pdev->dev, ahci_mask_port_map,
+			   &hpriv->mask_port_map);
+	ahci_get_port_mask(&pdev->dev, ahci_mask_port_ext,
+			   &hpriv->mask_port_ext);
 
 	ahci_save_initial_config(&pdev->dev, hpriv);
 }
-- 
2.53.0