Message-ID: <5099810D.9040902@web.de>
Date: Tue, 06 Nov 2012 22:28:45 +0100
From: =?ISO-8859-1?Q?S=F6ren_Moch?= <smoch@web.de>
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To: Lior Amsalem <alior@marvell.com>, Andrew Lunn <andrew@lunn.ch>,
        Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
        Ian Molton <ian.molton@codethink.co.uk>,
        Jason Cooper <jason@lakedaemon.net>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux@arm.linux.org.uk
CC: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
        Gregory Clement <gregory.clement@free-electrons.com>,
        m.szyprowski@samsung.com
Subject: Re: [PATCH V2 1/4] arm: mvebu: increase atomic coherent pool size
 for armada 370/XP
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resent as plain text, sorry.


 > For Armada 370/XP we have the same problem that for the commit
 > cb01b63, so we applied the same solution: "The default 256 KiB
 > coherent pool may be too small for some of the Kirkwood devices, so
 > increase it to make sure that devices will be able to allocate their
 > buffers with GFP_ATOMIC flag"

I see a regression from linux-3.5 to linux-3.6 and think there might be 
a fundamental problem
with this patch. On my Kirkwood system (guruplug server plus) with 
linux-3.6.2 I see following
errors and corresponding malfunction even with further increased (2M, 
4M) pool size:

Oct 19 00:41:22 guru kernel: ERROR: 4096 KiB atomic DMA coherent pool is 
too small!
Oct 19 00:41:22 guru kernel: Please increase it with coherent_pool= 
kernel parameter!

So I had to downgrade to linux-3.5 which is running without problems.

I use SATA and several DVB sticks (em28xx / drxk and dib0700).

I already sent this bug report to m.szyprowski and 
gregory.clementearlier, but
Sebastian suggested to send it to the mailing list and the responsible 
maintainers, too.

Please write to my e-mail directly if you have further questions or 
patches for me to test.

Regards,
Soeren

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