From: Scott Wood <scottwood@freescale•com>
To: Joakim Tjernlund <Joakim.Tjernlund@transmode•se>
Cc: linuxppc-dev@ozlabs•org, Li Yang <leoli@freescale•com>,
pku.leo@gmail•com, netdev@vger•kernel.org
Subject: Re: [PATCH] ucc_geth: Rework the TX logic.
Date: Mon, 30 Mar 2009 12:45:17 -0500 [thread overview]
Message-ID: <49D1052D.2050609@freescale.com> (raw)
In-Reply-To: <OF3127420C.081D4097-ONC1257589.00603E3D-C1257589.006093B3@transmode.se>
Joakim Tjernlund wrote:
> Scott Wood <scottwood@freescale•com> wrote on 30/03/2009 19:22:03:
>> Joakim Tjernlund wrote:
>>> gianfar does not seem to use in_/out_ functions for the BDs. Works
> just
>>> fine that too it seems.
>> It does now that it has explicit barriers in a few places. Before they
>
> In 2.6.29 or later?
No, it was earlier.
>> were added, it would sometimes fail under load. That was due to a
>> compiler reordering, but CPU reordering was possible as well.
>
> Does not the CPU skip reordering if the guarded bit is set?
The guarded bit is typically not set for DMA buffers. ucc_geth is a bit
different since descriptors are in MURAM which is ioremap()ed -- though
switching to a cacheable mapping with barriers should be a performance
improvement.
-Scott
next prev parent reply other threads:[~2009-03-30 17:45 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-26 17:44 [PATCH] ucc_geth: Rework the TX logic Joakim Tjernlund
2009-03-26 18:03 ` Anton Vorontsov
2009-03-26 18:26 ` Joakim Tjernlund
2009-03-27 9:45 ` Li Yang
2009-03-27 10:23 ` Joakim Tjernlund
2009-03-27 10:39 ` Li Yang
2009-03-27 11:39 ` Joakim Tjernlund
2009-03-27 13:26 ` Scott Wood
2009-03-30 16:38 ` Joakim Tjernlund
2009-03-30 17:22 ` Scott Wood
2009-03-30 17:34 ` Joakim Tjernlund
2009-03-30 17:45 ` Scott Wood [this message]
2009-03-30 18:42 ` Joakim Tjernlund
2009-03-30 19:32 ` Scott Wood
2009-03-31 9:07 ` Joakim Tjernlund
2009-03-31 10:58 ` Li Yang
2009-03-31 14:37 ` Scott Wood
2009-03-31 8:16 ` Li Yang
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