[PATCH 4.12 37/43] ahci: dont use MSI for devices with the silly Intel NVMe remapping scheme

Greg Kroah-Hartman
2017-09-08T13:38:02Z

From: Christoph Hellwig <hch@lst.de>

commit f723fa4e69920f6a5dd5fa0d10ce90e2f14d189c upstream.

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: d684a90d38e2 ("ahci: per-port msix support")
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/ata/ahci.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1467,7 +1467,14 @@ static void ahci_remap_check(struct pci_
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)