NAK: [PATCH 6/6] NVMe: Always use MSI/MSI-x interrupts

[Kamal Mostafa]

On Mon, Jul 18, 2016 at 09:08:41AM -0600, Tim Gardner wrote:
> From: Keith Busch <keith.busch at intel.com>
> 
> BugLink: http://bugs.launchpad.net/bugs/1602724
> 
> Multiple users have reported device initialization failure due the driver
> not receiving legacy PCI interrupts. This is not unique to any particular
> controller, but has been observed on multiple platforms.
> 
> There have been no issues reported or observed when with message signaled
> interrupts, so this patch attempts to use MSI-x during initialization,
> falling back to MSI. If that fails, legacy would become the default.
> 
> The setup_io_queues error handling had to change as a result: the admin
> queue's msix_entry used to be initialized to the legacy IRQ. The case
> where nr_io_queues is 0 would fail request_irq when setting up the admin
> queue's interrupt since re-enabling MSI-x fails with 0 vectors, leaving
> the admin queue's msix_entry invalid. Instead, return success immediately.
> 
> Reported-by: Tim Muhlemmer <muhlemmer at gmail.com>
> Reported-by: Jon Derrick <jonathan.derrick at intel.com>
> Signed-off-by: Keith Busch <keith.busch at intel.com>
> Signed-off-by: Jens Axboe <axboe at fb.com>
> (back ported from commit a5229050b69cfffb690b546c357ca5a60434c0c8)
> Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
> 
>  Conflicts:
> 	drivers/nvme/host/pci.c
> ---
>  drivers/nvme/host/pci.c         | 28 +++++++++-------


There's some unrelated cruft in this patch:

>  spl/rpm/redhat/spl-dkms.spec.in | 72 +----------------------------------------
>  spl/rpm/redhat/spl.spec.in      | 72 +----------------------------------------
>  3 files changed, 19 insertions(+), 153 deletions(-)
>  mode change 100644 => 120000 spl/rpm/redhat/spl-dkms.spec.in
>  mode change 100644 => 120000 spl/rpm/redhat/spl.spec.in

 -Kamal