Date: Mon, 03 Oct 2005 08:14:57 -0700
From: David Brownell <david-b@pacbell.net>
To: basicmark@yahoo.com, arjan@infradead.org
Subject: Re: [RFC][PATCH] SPI subsystem
Cc: linux-kernel@vger.kernel.org
References: <20051003105748.213.qmail@web33014.mail.mud.yahoo.com>
 <1128337656.17024.10.camel@laptopd505.fenrus.org>
In-Reply-To: <1128337656.17024.10.camel@laptopd505.fenrus.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Message-Id: <20051003151457.AD64FEE8CE@adsl-69-107-32-110.dsl.pltn13.pacbell.net>
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 886
Lines: 24

> From: Arjan van de Ven <arjan@infradead.org>
> Date: Mon, 03 Oct 2005 13:07:36 +0200
>
> please NEVER EVER do dma from or to a stack variable. It's not allowed
> on all architectures and it is really really bad practice in general
> anyway. 

Arjan, could you mention some Linuxes which don't allow it?

Every time the topic of DMA to/from stack comes up, the advice is
always to avoid it ... but so far as I recall, nobody's yet provided
us with an example where it actually doesn't work.

Failing such examples, it's normal to discount such dire warnings and
just plan to apply the relevant minor tweaks if/when they're needed.

- Dave


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