Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  ahci: disable FPDMA auto-activate optimization on NVIDIA AHCI

drivers/ata/ahci.c

@@ -3082,8 +3082,16 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	ahci_save_initial_config(pdev, hpriv);
 
 	/* prepare host */
-	if (hpriv->cap & HOST_CAP_NCQ)
-		pi.flags |= ATA_FLAG_NCQ | ATA_FLAG_FPDMA_AA;
+	if (hpriv->cap & HOST_CAP_NCQ) {
+		pi.flags |= ATA_FLAG_NCQ;
+		/* Auto-activate optimization is supposed to be supported on
+		   all AHCI controllers indicating NCQ support, but it seems
+		   to be broken at least on some NVIDIA MCP79 chipsets.
+		   Until we get info on which NVIDIA chipsets don't have this
+		   issue, if any, disable AA on all NVIDIA AHCIs. */
+		if (pdev->vendor != PCI_VENDOR_ID_NVIDIA)
+			pi.flags |= ATA_FLAG_FPDMA_AA;
+	}
 
 	if (hpriv->cap & HOST_CAP_PMP)
 		pi.flags |= ATA_FLAG_PMP;