From mboxrd@z Thu Jan  1 00:00:00 1970
From: Michael =?UTF-8?B?QsO8c2No?= <m@bues.ch>
Subject: Re: [Bugme-new] [Bug 38102] New: BUG kmalloc-2048: Poison
 overwritten
Date: Mon, 4 Jul 2011 16:31:34 +0200
Message-ID: <20110704163134.7f2180b2@maggie>
References: <bug-38102-10286@https.bugzilla.kernel.org/>
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Cc: Alexey Zaytsev <alexey.zaytsev@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	netdev@vger.kernel.org, Gary Zambrano <zambrano@broadcom.com>,
	bugme-daemon@bugzilla.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Pekka Pietikainen <pp@ee.oulu.fi>,
	Florian Schirmer <jolt@tuxbox.org>,
	Felix Fietkau <nbd@openwrt.org>, Michael Buesch <mb@bu3sch.de>
To: Eric Dumazet <eric.dumazet@gmail.com>
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On Mon, 04 Jul 2011 16:00:49 +0200
Eric Dumazet <eric.dumazet@gmail.com> wrote:
> > And an other question. Why so we have the logic to work-around the 1Gb
> > DMA limit instead of just setting the dma mask?
> 
> Your problem is in RX side : NIC actually writes to a buffer that is
> supposedly not its property.

The problem is on both sides, because some Linux architectures simply
do not support any DMA mask less than 32. This applied to i386 (IA32) last
time I looked.
The b44 DMA engine can only address 30-bits.