Re: [PATCH] fix e100 rx path on ARM (was [PATCH] e100 rx: or s and el bits)

[Jeff Garzik]

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 <[EMAIL PROTECTED]>
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 <[EMAIL PROTECTED]>


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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