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Date: Fri, 12 Nov 2010 12:25:01 -0800 (PST)
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Subject: Re: [PATCH 2/2] ucc_geth: Fix deadlock
From: David Miller <davem@davemloft.net>
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From: Anton Vorontsov <cbouatmailru@gmail.com>
Date: Fri, 12 Nov 2010 17:09:47 +0300

> On Fri, Nov 12, 2010 at 02:55:09PM +0100, Joakim Tjernlund wrote:
>> This script:
>>  while [ 1==1 ] ; do ifconfig eth0 up; usleep 1950000 ;ifconfig eth0 down; dmesg -c ;done
>> causes in just a second or two:
>> INFO: task ifconfig:572 blocked for more than 120 seconds.
> [...]
>> The reason appears to be ucc_geth_stop meets adjust_link as the
>> PHY reports PHY changes. I belive adjust_link hangs somewhere,
>> holding the PHY lock, because ucc_geth_stop disabled the
>> controller HW.
>> Fix is to stop the PHY before disabling the controller.
>> 
>> Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
> 
> It's unclear where exactly adjust_link() hangs, but the patch
> looks as the right thing overall.
> 
> Thanks!
> 
> Reviewed-by: Anton Vorontsov <cbouatmailru@gmail.com>

Applied.