Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

[platform/adaptation/renesas_rcar/renesas_kernel.git] / drivers / ata / ahci.c

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 74911c2..dc2756f 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1148,26 +1148,40 @@ static inline void ahci_gtf_filter_workaround(struct ata_host *host)
 {}
 #endif
 
-static int ahci_init_interrupts(struct pci_dev *pdev, struct ahci_host_priv *hpriv)
+static int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
+                        struct ahci_host_priv *hpriv)
 {
-       int rc;
-       unsigned int maxvec;
+       int rc, nvec;
 
-       if (!(hpriv->flags & AHCI_HFLAG_NO_MSI)) {
-               rc = pci_enable_msi_block_auto(pdev, &maxvec);
-               if (rc > 0) {
-                       if ((rc == maxvec) || (rc == 1))
-                               return rc;
-                       /*
-                        * Assume that advantage of multipe MSIs is negated,
-                        * so fallback to single MSI mode to save resources
-                        */
-                       pci_disable_msi(pdev);
-                       if (!pci_enable_msi(pdev))
-                               return 1;
-               }
-       }
+       if (hpriv->flags & AHCI_HFLAG_NO_MSI)
+               goto intx;
+
+       rc = pci_msi_vec_count(pdev);
+       if (rc < 0)
+               goto intx;
+
+       /*
+        * If number of MSIs is less than number of ports then Sharing Last
+        * Message mode could be enforced. In this case assume that advantage
+        * of multipe MSIs is negated and use single MSI mode instead.
+        */
+       if (rc < n_ports)
+               goto single_msi;
+
+       nvec = rc;
+       rc = pci_enable_msi_block(pdev, nvec);
+       if (rc)
+               goto intx;
 
+       return nvec;
+
+single_msi:
+       rc = pci_enable_msi(pdev);
+       if (rc)
+               goto intx;
+       return 1;
+
+intx:
        pci_intx(pdev, 1);
        return 0;
 }
@@ -1328,10 +1342,6 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
        hpriv->mmio = pcim_iomap_table(pdev)[ahci_pci_bar];
 
-       n_msis = ahci_init_interrupts(pdev, hpriv);
-       if (n_msis > 1)
-               hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
-
        /* save initial config */
        ahci_pci_save_initial_config(pdev, hpriv);
 
@@ -1386,6 +1396,10 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
         */
        n_ports = max(ahci_nr_ports(hpriv->cap), fls(hpriv->port_map));
 
+       n_msis = ahci_init_interrupts(pdev, n_ports, hpriv);
+       if (n_msis > 1)
+               hpriv->flags |= AHCI_HFLAG_MULTI_MSI;
+
        host = ata_host_alloc_pinfo(&pdev->dev, ppi, n_ports);
        if (!host)
                return -ENOMEM;