Date: Fri, 4 Mar 2011 12:43:48 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Greg KH <greg@kroah.com>
Cc: Matthew Wilcox <willy@linux.intel.com>, linux-kernel@vger.kernel.org
Subject: Re: [REVIEW] NVM Express driver
Message-ID: <20110304124348.6419c661@lxorguk.ukuu.org.uk>
In-Reply-To: <20110303222226.GA30966@kroah.com>
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On Thu, 3 Mar 2011 14:22:26 -0800
> > How would the driver know that it should call request_firmware()?
> > Do it every 60 seconds in case somebody's downloaded some new firmware?
> 
> Ick, no, just use the function provided that lets you create a firmware
> request and be notified when it is written to,
> request_firmware_nowait().  That is what it is there for.

Bunkum

It's there for automated loading of needed firmware

> Anyway, just use request_firmware_nowait(), you will be fine.

Not really. You've got no way with the request_firmware interface for the
user space and kernel space to reliably time objects together eg to do
user side work before a firmware load.

Almost all the other stuff in the kernel which is for firmware
programming as opposed to automatic loading is not using request_firmware
- and for good reasons like needing to be able to specify the path to the
object reliably - which cannot be done with namespaces.

>From a security perspective, a correctness perspective, for reliability
and managability request_firmware is the wrong interface for flashing new
firmware.

Alan
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