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Date: Sat, 15 May 2010 17:52:03 +0800
Message-ID: <AANLkTikFtb1j7x9-d-SpV8AAODQAxNAobIZePCQNLbip@mail.gmail.com>
Subject: Re: [PATCH 2/2] ath9k: fix dma sync in rx path
From: Ming Lei <tom.leiming@gmail.com>
To: Felix Fietkau <nbd@openwrt.org>
Cc: lrodriguez@atheros.com, linux-wireless@vger.kernel.org,
	linville@tuxdriver.com
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Sender: linux-wireless-owner@vger.kernel.org

2010/5/15 Felix Fietkau <nbd@openwrt.org>:
> The second part of your patch might be OK then (I'm not really sure).
> But the first part is definitely wrong, since with EDMA Rx, the
> descriptor data is part of the buffer, so the cache needs to be
> invalidated for every access until the status bit shows that it has been
> completed.
> This could probably be fixed by running dma_sync_single_for_device after
> an unsuccessful status bit check and also after the descriptor part has

Yes, dma_sync_single_for_device is needed to return buffer to device
if an unsuccessful status bit check is found.

> been zero'd out before passing the buffer on to the hw.

The patch does not touch this dma_sync_single_for_device.


-- 
Lei Ming