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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
Subject: Re: [PATCH 2/2] ath9k: fix dma sync in rx path
Date: Sat, 15 May 2010 17:52:03 +0800	[thread overview]
Message-ID: <AANLkTikFtb1j7x9-d-SpV8AAODQAxNAobIZePCQNLbip@mail.gmail.com> (raw)
In-Reply-To: <4BEE689A.9060102@openwrt.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

  reply	other threads:[~2010-05-15  9:52 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-05-14 13:15 [PATCH 1/2] ath9k: fix dma direction for map/unmap in ath_rx_tasklet tom.leiming
2010-05-14 13:16 ` [PATCH 2/2] ath9k: fix dma sync in rx path tom.leiming
2010-05-14 14:28   ` Felix Fietkau
2010-05-14 15:27     ` Ming Lei
2010-05-14 16:19       ` Felix Fietkau
2010-05-15  1:31         ` Ming Lei
2010-05-15  9:25           ` Felix Fietkau
2010-05-15  9:52             ` Ming Lei [this message]
2010-05-15 10:25               ` Ming Lei
2010-05-15 10:44                 ` Felix Fietkau
2010-05-27 13:51                 ` Felix Fietkau

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