From: Johannes Berg <johannes@sipsolutions.net>
To: "Jakub Kiciński" <moorray3@wp.pl>
Cc: Kalle Valo <kvalo@codeaurora.org>,
Felix Fietkau <nbd@openwrt.org>,
linux-wireless <linux-wireless@vger.kernel.org>,
Jakub Kicinski <kubakici@wp.pl>
Subject: Re: [PATCH 1/2] add mt7601u driver
Date: Mon, 04 May 2015 12:15:11 +0200 [thread overview]
Message-ID: <1430734511.2013.18.camel@sipsolutions.net> (raw)
In-Reply-To: <20150504120401.30835e07@north>
On Mon, 2015-05-04 at 12:04 +0200, Jakub Kiciński wrote:
> > Don't know how your buffers are set up, but if the DMA engine consumes
> > pages you could consider using paged RX instead of the memcpy().
>
> DMA engine can concatenate multiple frames into a single USB bulk
> transfer to a large continuous buffer. There is no way to request
> any alignment of the frames within that large buffer so I think paged
> RX is not an option.
You could probably still do it because the networking stack only
requires the *headers* to be aligned. But if they headers aren't in the
skb->data (skb->head) then they'll be pulled into that by the network
stack, where they'll be aligned.
johannes
next prev parent reply other threads:[~2015-05-04 10:15 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-02 13:01 [PATCH 0/2] add mt7601u driver moorray3
2015-05-02 13:01 ` [PATCH 1/2] " moorray3
2015-05-04 9:37 ` Johannes Berg
2015-05-04 10:04 ` Jakub Kiciński
2015-05-04 10:15 ` Johannes Berg [this message]
2015-05-05 0:49 ` Jakub Kiciński
2015-05-05 6:45 ` Johannes Berg
2015-05-05 10:44 ` Jakub Kiciński
2015-05-02 13:01 ` [PATCH 2/2] add mt7601u build infrastructure and co moorray3
2015-05-05 20:22 ` [PATCHv2 0/2] add mt7601u driver Jakub Kicinski
2015-05-05 20:22 ` [PATCHv2 1/2] " Jakub Kicinski
2015-05-05 20:22 ` [PATCHv2 2/2] add mt7601u kbuild and others Jakub Kicinski
2015-05-25 8:13 ` [PATCHv2 0/2] add mt7601u driver Kalle Valo
2015-05-25 9:35 ` Jakub Kiciński
2015-05-26 7:16 ` Johannes Berg
2015-05-25 9:34 ` [PATCHv3 " Jakub Kicinski
2015-05-25 9:34 ` [PATCHv3 1/2] " Jakub Kicinski
2015-05-25 9:34 ` [PATCHv3 2/2] add mt7601u kbuild and others Jakub Kicinski
2015-05-26 10:26 ` [PATCHv3 0/2] add mt7601u driver Kalle Valo
2015-05-26 9:16 ` [PATCHv4] " Jakub Kicinski
2015-05-28 8:36 ` Kalle Valo
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