Public bug reported:

== Comment: #16 - Guilherme Guaglianoni Piccoli <gpicc...@br.ibm.com> - 
2016-07-12 15:46:17 ==
NVMe adapters provide an interface to reset the controller after a firmware 
(aka microcode) activation, so the new firmware can be used without rebooting 
the whole system, for example.

To achieve this, firstly one activate the firmware with the command:
"nvme fw-activate -a 2 -s 2 /dev/nvme0".

And then, one can perform the reset right after the activate command succeed:
"echo 1 > /sys/class/nvme/nvme0/reset_controller".


The issue: in NVMe adapter from HGST vendor (PCI identification == 1c58:0003) 
this reset_controller feature does not work in recent kernels. The main reason 
is that the adapter is not dealing well with disabling the controller in the 
reset feature instead of shutdown it (as done in older kernels). To perform a 
successful reset, we need to delay 2 seconds before checking a specific bit 
during the reset process.

This delay was implemented as a per-device quirk in the nvme driver, and
is accepted upstream. Currently, it's present on Jens Axboe kernel tree,
ready to be merged on upstream 4.8 merge window.

We want to request the quirk's merge in Xenial's kernel. Below, the
commit information on Axboe's tree:

54adc01055b7 ("nvme/quirk: Add a delay before checking for adapter
readiness")

Link: https://git.kernel.org/cgit/linux/kernel/git/axboe/linux-
block.git/commit/?h=for-4.8/drivers&id=54adc01055b75ec8769c5a36574c7a0895c0c0b2


Thanks in advance,

Guilherme

** Affects: linux (Ubuntu)
     Importance: Undecided
     Assignee: Taco Screen team (taco-screen-team)
         Status: New


** Tags: architecture-ppc64le bugnameltc-136465 severity-high 
targetmilestone-inin16041

** Tags added: architecture-ppc64le bugnameltc-136465 severity-high
targetmilestone-inin16041

** Changed in: ubuntu
     Assignee: (unassigned) => Taco Screen team (taco-screen-team)

** Package changed: ubuntu => linux (Ubuntu)

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https://bugs.launchpad.net/bugs/1602726

Title:
  nvme - reset_controller is not working after adapter's firmware
  upgrade (adapter quirk is needed)

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