ahci: fix CAP.NP and PI handling

[linux-2.6-omap-h63xx.git] / drivers / ata / ahci.c

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 27c8d56111c2959b8d7f6cb64b9dccd85cee8a39..29e71bddd6ffdd12420b4749eb88f79fb51ead26 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -679,24 +679,20 @@ static void ahci_save_initial_config(struct pci_dev *pdev,
 
        /* cross check port_map and cap.n_ports */
        if (port_map) {
-               u32 tmp_port_map = port_map;
-               int n_ports = ahci_nr_ports(cap);
+               int map_ports = 0;
 
-               for (i = 0; i < AHCI_MAX_PORTS && n_ports; i++) {
-                       if (tmp_port_map & (1 << i)) {
-                               n_ports--;
-                               tmp_port_map &= ~(1 << i);
-                       }
-               }
+               for (i = 0; i < AHCI_MAX_PORTS; i++)
+                       if (port_map & (1 << i))
+                               map_ports++;
 
-               /* If n_ports and port_map are inconsistent, whine and
-                * clear port_map and let it be generated from n_ports.
+               /* If PI has more ports than n_ports, whine, clear
+                * port_map and let it be generated from n_ports.
                 */
-               if (n_ports || tmp_port_map) {
+               if (map_ports > ahci_nr_ports(cap)) {
                        dev_printk(KERN_WARNING, &pdev->dev,
-                                  "nr_ports (%u) and implemented port map "
-                                  "(0x%x) don't match, using nr_ports\n",
-                                  ahci_nr_ports(cap), port_map);
+                                  "implemented port map (0x%x) contains more "
+                                  "ports than nr_ports (%u), using nr_ports\n",
+                                  port_map, ahci_nr_ports(cap));
                        port_map = 0;
                }
        }
@@ -2201,7 +2197,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
        struct device *dev = &pdev->dev;
        struct ahci_host_priv *hpriv;
        struct ata_host *host;
-       int i, rc;
+       int n_ports, i, rc;
 
        VPRINTK("ENTER\n");
 
@@ -2255,7 +2251,14 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
        if (hpriv->cap & HOST_CAP_PMP)
                pi.flags |= ATA_FLAG_PMP;
 
-       host = ata_host_alloc_pinfo(&pdev->dev, ppi, fls(hpriv->port_map));
+       /* CAP.NP sometimes indicate the index of the last enabled
+        * port, at other times, that of the last possible port, so
+        * determining the maximum port number requires looking at
+        * both CAP.NP and port_map.
+        */
+       n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));
+
+       host = ata_host_alloc_pinfo(&pdev->dev, ppi, n_ports);
        if (!host)
                return -ENOMEM;
        host->iomap = pcim_iomap_table(pdev);