[PATCH] nvme-host: fix the updating of the firmware version

[Keith Busch]

On Thu, Jan 18, 2024 at 12:48:54PM +0100, Maurizio Lombardi wrote:
> The original code didn't update the firmware version if the
> "next slot" of the AFI register isn't zero or if the
> "current slot" field is zero; in those cases it assumed
> that a reset was needed.
> 
> However, the NVMe specification doesn't exclude the possibility that
> the "next slot" value is equal to the "current slot" value,
> meaning that the same firmware slot will be activated after performing
> a controller level reset; in this case a reset is clearly not
> necessary and we can safely update the firmware version.
> 
> Modify the code so the kernel will report that a Controller Level Reset
> is needed only in the following cases:
> 
> 1) If the "current slot" field is zero. This is invalid and means that
>    something is wrong, a reset is needed.
> 
> or
> 
> 2) if the "next slot" field isn't zero AND it's not equal to the
>    "current slot" value. This means that at the next reset a different
>    firmware slot will be activated.
> 
> Fixes: 983a338b96c8 ("nvme: update firmware version after commit")
> Signed-off-by: Maurizio Lombardi <mlombard at redhat.com>

Sorry I missed this one for this weeks pull request. It's now applied
for nvme-6.8 as the first commit for the next round.