From: Jeff Garzik <jeff@garzik•org>
To: Milton Miller <miltonm@bga•com>
Cc: "Kok, Auke" <auke-jan.h.kok@intel•com>,
e1000-devel@lists•sourceforge.net, netdev@vger•kernel.org,
Jesse Brandeburg <jesse.brandeburg@intel•com>,
Scott Feldman <sfeldma@pobox•com>,
John Ronciak <john.ronciak@intel•com>,
Jeff Kirsher <jeffrey.t.kirsher@intel•com>,
David Acker <dacker@roinet•com>, Jeff Garzik <jgarzik@pobox•com>
Subject: Re: [PATCH] fix e100 rx path on ARM (was [PATCH] e100 rx: or s and el bits)
Date: Fri, 15 Jun 2007 10:39:28 -0400 [thread overview]
Message-ID: <4672A4A0.4070806@garzik.org> (raw)
In-Reply-To: <5d7f4c9757838906e0adf01d77632f35@bga.com>
Milton Miller wrote:
>
> On Jun 6, 2007, at 4:28 AM, Milton Miller wrote:
>
>>
>> On Jun 5, 2007, at 9:26 PM, Kok, Auke wrote:
>>
>>> Kok, Auke wrote:
>>>>>
>>>> Hmm git-revert seems to do the job right. I checked it with git-show
>>>> | patch -p1 -R and the results look OK. The two patches on top of
>>>> the one we want to revert are unrelated enough to apply (manually it
>>>> shows some fuzz, but otherwise it's OK).
>>>> Jeff, please `git-revert d52df4a35af569071fda3f4eb08e47cc7023f094`
>>>> to revert the following patch for now:
>>>> ---
>>>> commit d52df4a35af569071fda3f4eb08e47cc7023f094
>>>> Author: Scott Feldman <sfeldma@pobox•com>
>>>> Date: Wed Nov 9 02:18:52 2005 -0500
>>>> [netdrvr e100] experiment with doing RX in a similar manner to
>>>> eepro100
>>>> I was going to say that eepro100's speedo_rx_link() does the
>>>> same DMA
>>>> abuse as e100, but then I noticed one little detail: eepro100
>>>> sets both
>>>> EL (end of list) and S (suspend) bits in the RFD as it chains
>>>> it to the
>>>> RFD list. e100 was only setting the EL bit. Hmmm, that's
>>>> interesting.
>>>> That means that if HW reads a RFD with the S-bit set, it'll
>>>> process
>>>> that RFD and then suspend the receive unit. The receive unit
>>>> will
>>>> resume when SW clears the S-bit. There is no need for SW to
>>>> restart
>>>> the receive unit. Which means a lot of the receive unit state
>>>> tracking
>>>> code in the driver goes away.
>>>> So here's a patch against 2.6.14. (Sorry for inlining it; the
>>>> mailer
>>>> I'm using now will mess with the word wrap). I can't test this on
>>>> XScale (unless someone has an e100 module for Gumstix :) . It
>>>> should
>>>> be doing exactly what eepro100 does with RFDs. I don't believe
>>>> this
>>>> change will introduce a performance hit because the S-bit and
>>>> EL-bit go
>>>> hand-in-hand meaning if we're going to suspend because of the
>>>> S- bit,
>>>> we're on the last resource anyway, so we'll have to wait for SW
>>>> to
>>>> replenish.
>>>> (cherry picked from 29e79da9495261119e3b2e4e7c72507348e75976
>>>> commit)
>>>> ---
>>>
>>> A little bit more is needed to explain why we're reverting it for
>>> now. Jeff, please insert this into the revert commit.
>>>
>>> Auke
>>>
>>> --
>>> This patch attempted to fix e100 for non-cache coherent memory
>>> architectures by using the cb style code that eepro100 had and using
>>> the EL and s bits from the RFD list. Unfortunately the hardware
>>> doesn't work exactly like this and therefore this patch actually
>>> breaks e100 on those systems.
>>
>> on all systems. (Both the &| typo and the removed restart logic).
>>
>>> Reverting the change brings it back to the previously known good
>>> state for 2.6.22. The pending rewrite in progress to this code can
>>> then be safely merged later.
>>>
>>> Signed-off-by: Auke Kok <auke-jan.h.kok@intel•com>
>>>
>
> Jeff I don't see this in netdev upstream-fixes. Are you waiting on Auke
> to respond to this?
It should now be upstream, as of a day or two ago.
Sorry for the delaying, was travelling, and wound up accidentally losing
Auke's commit description.
Jeff
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next prev parent reply other threads:[~2007-06-15 14:39 UTC|newest]
Thread overview: 51+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-05-01 11:24 [PATCH] e100 rx: or s and el bits Milton Miller
2007-05-01 15:01 ` David Acker
2007-05-02 20:21 ` David Acker
2007-05-04 21:43 ` David Acker
2007-05-06 6:36 ` Milton Miller
2007-05-07 15:27 ` David Acker
2007-05-14 18:26 ` [PATCH] fix e100 rx path on ARM (was [PATCH] e100 rx: or s and el bits) David Acker
2007-05-18 1:54 ` Jeff Garzik
2007-05-18 3:47 ` Kok, Auke
2007-05-18 14:07 ` David Acker
2007-05-18 14:20 ` David Acker
2007-05-18 15:29 ` Kok, Auke
2007-05-18 15:47 ` David Acker
2007-05-18 15:59 ` Kok, Auke
2007-05-18 17:11 ` David Acker
2007-05-18 17:47 ` Kok, Auke
2007-05-21 17:35 ` Milton Miller
2007-05-21 17:45 ` Kok, Auke
2007-05-22 16:51 ` Milton Miller
2007-05-22 22:07 ` David Acker
2007-05-23 14:02 ` Milton Miller
2007-05-23 21:32 ` David Acker
2007-05-24 5:26 ` Milton Miller
2007-05-24 11:21 ` Milton Miller
2007-05-24 12:51 ` David Acker
2007-05-24 14:25 ` Milton Miller
2007-05-29 15:58 ` David Acker
2007-05-30 8:26 ` Milton Miller
2007-06-01 20:45 ` David Acker
2007-06-01 21:13 ` Jeff Garzik
2007-06-01 22:13 ` Kok, Auke
2007-06-04 9:03 ` Milton Miller
2007-06-05 13:34 ` David Acker
2007-06-05 16:14 ` Milton Miller
2007-08-27 17:34 ` Kok, Auke
2007-08-27 18:32 ` David Acker
2007-06-05 16:14 ` Milton Miller
2007-06-05 17:27 ` Kok, Auke
2007-06-05 17:39 ` Jeff Garzik
2007-06-05 17:42 ` David Acker
2007-06-05 17:43 ` Kok, Auke
2007-06-05 17:56 ` Milton Miller
2007-06-05 23:33 ` Kok, Auke
2007-06-05 23:44 ` Jeff Garzik
2007-06-06 2:26 ` Kok, Auke
2007-06-06 9:28 ` Milton Miller
2007-06-11 15:58 ` Milton Miller
2007-06-15 14:39 ` Jeff Garzik [this message]
2007-05-24 12:44 ` David Acker
2007-05-24 4:13 ` Milton Miller
2007-05-01 15:21 ` [PATCH] e100 rx: or s and el bits Kok, Auke
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