Make use of the new pci_enable_msi_block_part() interface
and conserve on othewise wasted interrupt resources for 10
of 16 unused MSI vectors on Intel chipsets.
Signed-off-by: Alexander Gordeev <agord...@redhat.com>
---
drivers/ata/ahci.c | 46 +++++++++++++++++++++++++++-------------------
1 files changed, 27 insertions(+), 19 deletions(-)
diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index db4380d..a6bb618 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1091,26 +1091,34 @@ static inline void ahci_gtf_filter_workaround(struct
ata_host *host)
{}
#endif
-int ahci_init_interrupts(struct pci_dev *pdev, struct ahci_host_priv *hpriv)
+int ahci_init_interrupts(struct pci_dev *pdev, unsigned int n_ports,
+ struct ahci_host_priv *hpriv)
{
int rc;
unsigned int maxvec;
- 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;
+
+ maxvec = pci_get_msi_cap(pdev);
+ if (maxvec < 0)
+ goto intx;
+ if (maxvec < n_ports)
+ goto single_msi;
+
+ rc = pci_enable_msi_block_part(pdev, n_ports, maxvec);
+ if (rc < 0)
+ goto intx;
+ if (rc)
+ goto single_msi;
+
+ return maxvec;
+single_msi:
+ if (!pci_enable_msi(pdev))
+ return 1;
+
+intx:
pci_intx(pdev, 1);
return 0;
}
@@ -1277,10 +1285,6 @@ 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);
@@ -1327,6 +1331,10 @@ 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;
--
1.7.7.6
--
Regards,
Alexander Gordeev
agord...@redhat.com
--
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