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From: Shuah Khan <shuah.khan@hp.com>
To: Fengguang Wu <fengguang.wu@intel.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
	"e1000-devel@lists.sourcefor..."
	<e1000-devel@lists.sourceforge.net>,
	shuahkhan@gmail.com
Subject: Re: WARNING: at lib/dma-debug.c:948 check_unmap()
Date: Mon, 15 Oct 2012 10:06:13 -0600	[thread overview]
Message-ID: <1350317173.3452.9.camel@lorien2> (raw)
In-Reply-To: <20121014170226.GA3235@localhost>

On Mon, 2012-10-15 at 01:02 +0800, Fengguang Wu wrote:
> Hi Shuah,
> 
> FYI, your debug commit
> 
> commit 224d4b5563b005836628b1c02ebe374684df118f
> Author: Shuah Khan <shuah.khan@hp.com>
> Date:   Fri Oct 12 15:23:05 2012 +1100
> 
>     dma-debug: new interfaces to debug dma mapping errors
> 
> triggers the below warning. Hopefully you know better than me the real
> issue and relevant developers to CC.
> 

This warning indicates that the driver failed to check dma mapping error
on a buffer returned by dma_map_single() or dma_map_page() call. Looking
at the the area where mapping is done, it appears it does call
dma_mapping_error(). It does allocate several buffers in a loop, so it
not obvious to me why the warning is showing up. I will follow-up on
this to make sure it is not a false alarm, before I get the driver team
involved. Thanks for reporting it.

-- Shuah


      reply	other threads:[~2012-10-15 16:06 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-14 17:02 WARNING: at lib/dma-debug.c:948 check_unmap() Fengguang Wu
2012-10-15 16:06 ` Shuah Khan [this message]

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