Subject: Re: [PATCH] 3/3 maple: update bus driver to support Dreamcast VMU
From: Adrian McMenamin <adrian@newgolddream.dyndns.info>
To: =?ISO-8859-1?Q?J=F6rn?= Engel <joern@logfs.org>
Cc: Paul Mundt <lethal@linux-sh.org>, Greg KH <greg@kroah.com>,
       dwmw2 <dwmw2@infradead.org>, LKML <linux-kernel@vger.kernel.org>,
       MTD <linux-mtd@lists.infradead.org>,
       linux-sh <linux-sh@vger.kernel.org>, Andrew Morton <akpm@osdl.org>
In-Reply-To: <20080324170707.GH2899@logfs.org>
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Date: Mon, 24 Mar 2008 17:18:13 +0000
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On Mon, 2008-03-24 at 18:07 +0100, Jörn Engel wrote:
> On Mon, 24 March 2008 17:04:29 +0100, Jörn Engel wrote:
> > 
> > Then we should be fine.  I'll try to beat the code into submission.
> 
> And here go two more interesting patches.  The first is removing all
> locking from the mtd driver.  Since the existing locking code is nearly
> impossibly to verify, I'd rather have something simple and wrong than
> something complicated and wrong.
> 
> The second rearranges the list locking a bit.  Previously it was
> possible to touch maple_waitq or maple_sentq without holding the lock.
> With my limited understanding of the driver, the second patch may
> already be enough to prevent the type of corruption you've been seeing.
> 
> Jörn
> 


These will fail.

Removing the locks just about guarantees memory corruption and
maple_waitq is not the issue - it is the objects held in maple_waitq
that are the issue.

I have an idea though, so let me hack at it

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