From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754806AbYIXQ6R (ORCPT ); Wed, 24 Sep 2008 12:58:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751681AbYIXQ6F (ORCPT ); Wed, 24 Sep 2008 12:58:05 -0400 Received: from yw-out-2324.google.com ([74.125.46.31]:47385 "EHLO yw-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751166AbYIXQ6E (ORCPT ); Wed, 24 Sep 2008 12:58:04 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references:x-google-sender-auth; b=S7cnGXJeqc3PRkW4WKmPRTNARAU70efyePL4K8lNMyKR2aipRMvRi8JE6M4f4e1eXT N5Yd5t02RBrKGHpH7zPu0Wax4jDHiI9CsJ8DPn9aEaPeqMJ/tt02DcjR8FkDWLRaX+QE D5QcGEzwSdjxewRfzjPEZ6nSIUnXPqno5a87g= Message-ID: Date: Wed, 24 Sep 2008 09:58:02 -0700 From: "Dan Williams" To: "Timur Tabi" Subject: Re: [PATCH] fsldma: remove internal self-test from Freescale Elo DMA driver Cc: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org, scottwood@freescale.com, galak@kernel.crashing.org, leoli@freescale.com In-Reply-To: <1222201756-21374-1-git-send-email-timur@freescale.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1222201756-21374-1-git-send-email-timur@freescale.com> X-Google-Sender-Auth: a117085906d158b4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 23, 2008 at 1:29 PM, Timur Tabi wrote: > The Freescale Elo DMA driver runs an internal self-test before registering > the channels with the DMA engine. This self-test has a fundemental flaw in > that it calls the DMA engine's callback functions directly before the > registration. However, the registration initializes some variables that the > callback functions uses, namely the device struct. > > The code works today because there are two device structs: the one created > by the DMA engine, and one created by the Open Firmware (OF) subsystem. The > self-test currently uses the device struct created by OF. However, in the > future, some of the device structs created by OF will be eliminated. > This means that the self-test will only have access to the device struct > created by the DMA engine. But this device struct isn't initialized when > the self-test runs, and this causes a kernel panic. > > Since there is already a DMA test module (dmatest), the internal self-test > code is not useful anyway. It is extremely unlikely that the test will fail > in normal usage. It may have been helpful during development, but not any more. > > Signed-off-by: Timur Tabi > --- > > This patch is for 2.6.28. Applied to the 'next' [1] branch. Thanks, Dan [1] http://git.kernel.org/?p=linux/kernel/git/djbw/async_tx.git;a=shortlog;h=next