Date: Fri, 1 Sep 2017 08:57:50 +0200
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Piotr Gregor <piotrgregor@rsyncme.org>
Cc: linux-kernel@vger.kernel.org, devel@driverdev.osuosl.org
Subject: Re: [PATCH] drivers: staging: Add driver for Amplicon PCIe215
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On Thu, Aug 31, 2017 at 05:54:58PM +0100, Piotr Gregor wrote:
> This is a small and simple driver for handling of external
> interrupt signal asserted on pins of Amplicon's PCIe215 board.
> There is already a Comedi driver subsystem in kernel which handles
> that (and more) board, but that framework while offering more
> flexibility brings also additional complexity at the cost of being generic.
> 
> In some cases the simpler, more compact solution may be preferred.

Note, having different drivers for the same hardware platform in the
kernel tree is a mess, and generally discouraged.  I've handled this in
the past and we hated every minute of it.

What is wrong with the comedi interface instead?

And custom ioctls for a single hardware device is horrid, what's wrong
with using the uio interface for something like this?

And finally, why staging?  While I know I wouldn't accept merging this
into the main portion of the kernel, why do you feel that adding this to
drivers/staging/ is ok?  What's so wrong with it (well, becides the
previous questions), that dumping it here is the properly location?

> The purpose of this driver is therefore to handle interrupt
> feature of the PCIe215, while being small, simple and reliable.

Why isn't comedi reliable?

thanks,

greg k-h