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From: khollan <khollan@daktronics.com>
To: linuxppc-embedded@ozlabs.org
Subject: RE: Xilinx Temac Timer ?
Date: Thu, 27 Mar 2008 12:31:57 -0700 (PDT)	[thread overview]
Message-ID: <16332251.post@talk.nabble.com> (raw)
In-Reply-To: <20080326194837.096A66A80EE@mail125-dub.bigfish.com>




John Linn wrote:
> 
> Hi Kevin,
> 
> I didn't write the code but I know the driver somewhat.
> 
> I think the intention of stopping the timer is to prevent the reentrancy
> as the comment says because there is a function, gmii_poll, that is
> setup on the timer to go read the phy registers to see if anything
> changed in the phy. 
> 
> Stopping the timer prevents a phy read from happening in gmii_poll in
> the middle of the ioctl phy read which could hose things up.
> 
> I don't see why you couldn't change that timer stop to some other form
> of synchronization/mutual exclusion so that the phy reads don't collide.
> 
> As I look at it, it appears to me the spinlock should provide the
> synchronization needed without stopping the timer, but maybe I'm missing
> something. I CCed John Bonesio as he's the guy that developed this code
> I believe and maybe he'll have more insight here.
> 
> Thanks,
> John
> 
I removed the timer code, and it seems to be working correctly, hopefully
the spin lock is all I need to lock out the polling function.  Thanks for
you help

Kevin
-- 
View this message in context: http://www.nabble.com/Xilinx-Temac-Timer---tp16306218p16332251.html
Sent from the linuxppc-embedded mailing list archive at Nabble.com.

  reply	other threads:[~2008-03-27 19:32 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-26 17:02 Xilin Temac Timer ? khollan
2008-03-26 19:48 ` Xilinx " John Linn
2008-03-27 19:31   ` khollan [this message]
2008-03-31 14:33 ` JFFS2 root-fs Georg Schardt

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