From mboxrd@z Thu Jan  1 00:00:00 1970
From: Larry Finger <Larry.Finger@lwfinger.net>
Date: Wed, 24 Aug 2011 11:53:51 -0500
Subject: [RFT][PATCH] b43: use 8K buffers for 64-bit DMA to workaround
	hardware bug
In-Reply-To: <20110824180611.36af5a83@milhouse>
References: <1314201438-12125-1-git-send-email-zajec5@gmail.com>
	<20110824180611.36af5a83@milhouse>
Message-ID: <4E552C9F.1020104@lwfinger.net>
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To: =?UTF-8?B?TWljaGFlbCBCw7xzY2g=?= <m@bues.ch>
Cc: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <zajec5@gmail.com>, linux-wireless@vger.kernel.org, b43-dev@lists.infradead.org, David Woodhouse <dwmw2@infradead.org>

On 08/24/2011 11:06 AM, Michael B?sch wrote:
> On Wed, 24 Aug 2011 17:57:18 +0200
> Rafa? Mi?ecki<zajec5@gmail.com>  wrote:
>
>> +	/* For unknown reasons - possibly a hardware error - the BCM4311 rev
>>   	 * 02, which uses 64-bit DMA, needs the ring buffer in very low memory,
>>   	 * which accounts for the GFP_DMA flag below.
>> -	 *
>> -	 * The flags here must match the flags in free_ringmemory below!
>>   	 */
>> +	gfp_t flags = GFP_KERNEL;
>>   	if (ring->type == B43_DMA_64BIT)
>>   		flags |= GFP_DMA;
>
>
> Did somebody actually re-evaluate this?
> I still believe that this is not a hardware error, but rather a software
> bug in the DMA allocator that probably is fixed already.
>
> Larry, I think you added this. Do you still have the device that triggered this?

Yes, I do. I'll test the BCM4311 with the GFP_KERNEL flag.

Larry