linux-kernel - Re: [GIT PATCH] more Driver core patches for 2.6.19

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20061214115105.GA8742@dspnet.fr.eu.org>
Date:	Thu, 14 Dec 2006 12:51:05 +0100
From:	Olivier Galibert <galibert@...ox.com>
To:	linux-kernel@...r.kernel.org
Subject: Re: [GIT PATCH] more Driver core patches for 2.6.19

On Thu, Dec 14, 2006 at 10:56:03AM +0100, Hans-Jürgen Koch wrote:
> A small German manufacturer produces high-end AD converter cards. He sells
> 100 pieces per year, only in Germany and only with Windows drivers. He would
> now like to make his cards work with Linux. He has two driver programmers
> with little experience in writing Linux kernel drivers. What do you tell him?
> Write a large kernel module from scratch? Completely rewrite his code 
> because it uses floating point arithmetics?

Write a small kernel module which:
- create a device node per-card
- read the data from the A/D as fast as possible and buffer it in main
  memory without touching it
- implements a read interface to read data from the buffer
- implement ioctls for whatever controls you need

And that's it.  All the rest can be done in userspace, safely, with
floating point, C++ and everything.  If the driver programmers are
worth their pay, their driver is probably already split logically at
where the userspace-kernel interface would be.

And small means small, like 200 lines or so, more if you want to have
fun with sysfs, poll, aio and their ilk, but that's not a necessity.

  OG.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/