From: David Miller <davem@davemloft.net>
To: ratbert.chuang@gmail.com
Cc: mirqus@gmail.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, bhutchings@solarflare.com,
eric.dumazet@gmail.com, joe@perches.com, dilinger@queued.net,
ratbert@faraday-tech.com
Subject: Re: [PATCH v4] net: add Faraday FTMAC100 10/100 Ethernet driver
Date: Wed, 23 Feb 2011 23:51:29 -0800 (PST) [thread overview]
Message-ID: <20110223.235129.02262510.davem@davemloft.net> (raw)
In-Reply-To: <AANLkTimorcNAEbSpuE_dUXKuOBZDcDcGSJ2cGefniThc@mail.gmail.com>
From: Po-Yu Chuang <ratbert.chuang@gmail.com>
Date: Thu, 24 Feb 2011 15:27:55 +0800
> I guess the problem is because a HW restriction that the rx buffer must be
> 64 bits aligned. Since I cannot make rx buffer starts at offset 2 bytes, the
> IP header, TCP header and data are not 4 bytes aligned. The performance
> drops drastically.
I cannot believe that after 20 years of commodity ethernet networking
chips were first designed, people are still designing hardware that
doesn't do this right.
Just emit garbage bytes into the sub-word alignment padding if the chip
wants to word align it's DMA writes.
Even the 15 year old Dec Tulip chips do this properly.
next prev parent reply other threads:[~2011-02-24 7:51 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-13 11:49 [PATCH] net: add Faraday FTMAC100 10/100 Ethernet driver Po-Yu Chuang
2011-01-13 14:03 ` Ben Hutchings
2011-01-14 5:37 ` Po-Yu Chuang
2011-01-13 14:22 ` Eric Dumazet
2011-01-13 16:29 ` Andres Salomon
2011-01-14 6:44 ` Po-Yu Chuang
2011-01-14 6:56 ` Po-Yu Chuang
2011-01-13 15:39 ` Joe Perches
2011-01-14 6:35 ` Po-Yu Chuang
[not found] ` <1294959948.4114.189.camel@Joe-Laptop>
2011-01-14 6:49 ` Po-Yu Chuang
2011-01-17 9:21 ` [PATCH v2] " Po-Yu Chuang
2011-01-17 17:19 ` Joe Perches
2011-01-19 9:40 ` Po-Yu Chuang
2011-01-19 12:46 ` Ben Hutchings
2011-01-19 16:41 ` Joe Perches
2011-01-20 5:30 ` Po-Yu Chuang
2011-01-20 8:46 ` Joe Perches
2011-01-17 17:29 ` Eric Dumazet
2011-01-17 18:58 ` Ben Hutchings
2011-01-17 20:39 ` Eric Dumazet
2011-01-17 18:21 ` Eric Dumazet
2011-01-18 3:08 ` Po-Yu Chuang
2011-01-19 9:20 ` Po-Yu Chuang
2011-01-20 15:30 ` [PATCH v3] " Po-Yu Chuang
2011-01-20 15:35 ` Eric Dumazet
2011-01-20 15:43 ` Po-Yu Chuang
2011-01-20 15:41 ` Eric Dumazet
2011-01-20 15:54 ` Po-Yu Chuang
2011-01-20 17:56 ` Joe Perches
2011-01-21 3:35 ` Po-Yu Chuang
2011-01-20 19:00 ` Joe Perches
2011-01-21 5:03 ` Po-Yu Chuang
[not found] ` <1295592411.6795.10.camel@Joe-Laptop>
2011-01-21 7:06 ` Po-Yu Chuang
2011-01-20 19:01 ` Michał Mirosław
2011-01-21 3:37 ` Po-Yu Chuang
2011-01-21 7:55 ` [PATCH v4] " Po-Yu Chuang
2011-01-21 9:08 ` Eric Dumazet
2011-01-24 8:07 ` Po-Yu Chuang
2011-01-21 12:26 ` Michał Mirosław
2011-01-24 8:26 ` Po-Yu Chuang
2011-01-24 20:22 ` Michał Mirosław
2011-01-25 2:46 ` Po-Yu Chuang
2011-02-01 3:56 ` Po-Yu Chuang
2011-02-01 4:35 ` David Miller
2011-02-24 7:27 ` Po-Yu Chuang
2011-02-24 7:51 ` David Miller [this message]
2011-02-24 8:07 ` Po-Yu Chuang
2011-02-24 8:22 ` Eric Dumazet
2011-02-24 9:29 ` [PATCH ref0] " Po-Yu Chuang
2011-02-24 17:39 ` Eric Dumazet
2011-02-24 17:48 ` Eric Dumazet
2011-02-25 2:32 ` Po-Yu Chuang
2011-02-25 9:45 ` Po-Yu Chuang
2011-02-25 10:52 ` Eric Dumazet
2011-02-25 18:34 ` David Miller
2011-02-25 18:45 ` Eric Dumazet
2011-02-25 18:47 ` Eric Dumazet
2011-03-01 5:45 ` Po-Yu Chuang
2011-03-01 5:53 ` Eric Dumazet
2011-02-25 9:57 ` [PATCH v6] " Po-Yu Chuang
2011-02-25 11:40 ` Eric Dumazet
2011-03-01 5:20 ` Po-Yu Chuang
2011-03-01 5:26 ` Eric Dumazet
2011-03-01 5:45 ` Eric Dumazet
2011-03-01 5:51 ` Po-Yu Chuang
2011-03-01 5:54 ` Eric Dumazet
2011-03-01 5:59 ` Eric Dumazet
2011-03-01 6:48 ` [PATCH] " Po-Yu Chuang
2011-03-01 7:27 ` Eric Dumazet
2011-03-03 20:19 ` David Miller
2011-02-24 18:43 ` [PATCH v4] " David Miller
2011-01-24 12:39 ` [PATCH v5] " Po-Yu Chuang
2011-01-24 15:07 ` Eric Dumazet
2011-01-25 2:46 ` Po-Yu Chuang
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