ahci: don't use MSI for devices with the silly Intel NVMe remapping s…

…cheme

Intel AHCI controllers that also hide NVMe devices in their bar
can't use MSI interrupts, so disable them.

Reported-by: John Loy <john.robert.loy@gmail.com>
Tested-by: John Loy <john.robert.loy@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fixes: d684a90 ("ahci: per-port msix support")
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/ahci.c

@@ -1469,7 +1469,14 @@ static void ahci_remap_check(struct pci_dev *pdev, int bar,
 		return;
 
 	dev_warn(&pdev->dev, "Found %d remapped NVMe devices.\n", count);
-	dev_warn(&pdev->dev, "Switch your BIOS from RAID to AHCI mode to use them.\n");
+	dev_warn(&pdev->dev,
+		 "Switch your BIOS from RAID to AHCI mode to use them.\n");
+
+	/*
+	 * Don't rely on the msi-x capability in the remap case,
+	 * share the legacy interrupt across ahci and remapped devices.
+	 */
+	hpriv->flags |= AHCI_HFLAG_NO_MSI;
 }
 
 static int ahci_get_irq_vector(struct ata_host *host, int port)