Date: Thu, 3 Mar 2011 17:07:35 -0500
From: Matthew Wilcox <willy@linux.intel.com>
To: Greg KH <greg@kroah.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [REVIEW] NVM Express driver
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On Thu, Mar 03, 2011 at 01:51:55PM -0800, Greg KH wrote:
> Heh, no, well, submit_io should just go through the block layer and not
> be a separate ioctl, right?

Just like with SG_IO, there are reasons to do I/Os without going through
the block layer.

> > There's a bit of an impedence mismatch there.  Think of this as
> > being drive firmware instead of controller firmware.  This isn't for
> > request_firmware() kind of uses, it's for some admin tool to come along
> > and tell the drive "Oh, here's some new firmware for you".
> 
> That's fine, request_firmware will work wonderfully for that.

How would the driver know that it should call request_firmware()?
Do it every 60 seconds in case somebody's downloaded some new firmware?

> > If you look at the spec [1], you'll see there are a number of firmware
> > slots in the device, and it's up to the managability utility to decide
> > which one to replace or activate.  I dno't think you want to pull all
> > that gnarly decision making code into the kernel, do you?
> > 
> > [1] http://download.intel.com/standards/nvmhci/NVM_Express_1_0_Gold.pdf
> 
> No, just export multiple "slots" as firmware devices ready to be filled
> in by userspace whenever it wants/needs to.  The management utility can
> just dump the firmware to those sysfs files when it determines it needs
> to update the firmware, no decision making in the kernel at all.

OK ... glad we decided to limit the number of slots.  I still don't see
(in Documentation/firmware_class/README) how this works for user-initiated
firmware updates rather than kernel-initiated.
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