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From: "Michael Büsch" <m@bues.ch>
To: "Rafał Miłecki" <zajec5@gmail.com>
Cc: linux-wireless@vger.kernel.org, b43-dev@lists.infradead.org,
	David Woodhouse <dwmw2@infradead.org>,
	Larry Finger <Larry.Finger@lwfinger.net>
Subject: [RFT][PATCH] b43: use 8K buffers for 64-bit DMA to workaround hardware bug
Date: Wed, 24 Aug 2011 18:06:11 +0200	[thread overview]
Message-ID: <20110824180611.36af5a83@milhouse> (raw)
In-Reply-To: <1314201438-12125-1-git-send-email-zajec5@gmail.com>

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?

-- 
Greetings, Michael.

  reply	other threads:[~2011-08-24 16:06 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-24 15:57 [RFT][PATCH] b43: use 8K buffers for 64-bit DMA to workaround hardware bug Rafał Miłecki
2011-08-24 16:06 ` Michael Büsch [this message]
2011-08-24 16:53   ` Larry Finger
2011-08-26 13:28 ` David Woodhouse

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