From: David Miller <davem@davemloft.net>
To: risto.suominen@gmail.com
Cc: netdev@vger.kernel.org
Subject: Re: [PATCH 002/002] de2104x: support for systems lacking cache coherence
Date: Sun, 08 Feb 2009 23:45:02 -0800 (PST) [thread overview]
Message-ID: <20090208.234502.197065045.davem@davemloft.net> (raw)
In-Reply-To: <46e1c7760902082327s1c498ac3w56939960ac306426@mail.gmail.com>
From: Risto Suominen <risto.suominen@gmail.com>
Date: Mon, 9 Feb 2009 09:27:49 +0200
> Add a configurable Descriptor Skip Length for systems that lack cache coherence.
>
> Signed-off-by: Risto Suominen <Risto.Suominen@gmail.com>
I really don't see why this patch could possibly be necessary.
On systems that lack cache coherence:
1) {pci,dma}_alloc_{consistent,coherent}() give kernel mappings of
the buffer with the cache disabled. Therefore the device and
and cpu see the correct data.
2) {pci,dma}_{map,unmap}_{single,sg}() do the appropriate cache
flushing.
Explicit syncing between cpu and device can be performed
using {pci,dma}_sync_{single,sg}() as needed.
Therefore, this patch is superfluous.
next prev parent reply other threads:[~2009-02-09 7:45 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <46e1c7760902071330i5362fe4fvd99fc7075fc666d3@mail.gmail.com>
2009-02-09 7:27 ` Fwd: [PATCH 002/002] de2104x: support for systems lacking cache coherence Risto Suominen
2009-02-09 7:45 ` David Miller [this message]
2009-02-09 8:22 ` Risto Suominen
2009-02-09 8:29 ` David Miller
2009-02-09 8:35 ` Risto Suominen
2009-02-09 16:58 ` Krzysztof Halasa
2009-02-09 19:22 ` Risto Suominen
2009-02-09 22:51 ` David Miller
2009-02-10 1:45 ` Krzysztof Halasa
2009-02-10 1:50 ` David Miller
2009-02-10 23:21 ` David Miller
2009-02-11 12:18 ` Risto Suominen
2009-02-11 12:31 ` Risto Suominen
2009-02-11 21:39 ` David Miller
2009-02-13 3:42 ` Benjamin Herrenschmidt
2009-02-10 1:01 ` Andrew Morton
2009-02-10 1:07 ` David Miller
2009-02-10 7:16 ` Risto Suominen
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