Patch "ahci: don't use MSI for devices with the silly Intel NVMe remapping scheme" has been added to the 4.12-stable tree

Patch "ahci: don't use MSI for devices with the silly Intel NVMe remapping scheme" has been added to the 4.12-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

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

to the 4.12-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ahci-don-t-use-msi-for-devices-with-the-silly-intel-nvme-remapping-scheme.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From f723fa4e69920f6a5dd5fa0d10ce90e2f14d189c Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 5 Sep 2017 18:46:47 +0200
Subject: ahci: don't use MSI for devices with the silly Intel NVMe remapping scheme

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)


Patches currently in stable-queue which might be from hch@lst.de are

queue-4.12/ahci-don-t-use-msi-for-devices-with-the-silly-intel-nvme-remapping-scheme.patch