Message-ID: <4FAC26A5.3050606@intel.com>
Date: Thu, 10 May 2012 13:35:49 -0700
From: Alexander Duyck <alexander.h.duyck@intel.com>
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To: Jonathan Nieder <jrnieder@gmail.com>
CC: David Miller <davem@davemloft.net>, gregkh@linuxfoundation.org,
        linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        torvalds@linux-foundation.org, akpm@linux-foundation.org,
        alan@lxorguk.ukuu.org.uk, stephen.s.ko@intel.com,
        jeffrey.t.kirsher@intel.com
Subject: Re: [ 33/52] net: Fix issue with netdev_tx_reset_queue not resetting
 queue from XOFF state
References: <20120510173135.772550373@linuxfoundation.org> <4FAC0EA7.3000100@intel.com> <20120510.145510.1040533529305157641.davem@davemloft.net> <20120510194658.GA9858@burratino>
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On 05/10/2012 12:46 PM, Jonathan Nieder wrote:
> David Miller wrote:
>> From: Alexander Duyck <alexander.h.duyck@intel.com>
>>> All of the changes in igb are unnecessary.  I think they can be dropped
>>> from the patch as they have already been reverted from the latest
>>> net-next.  The only change that is really needed is the piece in
>>> netdevice.h below.
>> Does it hurt?  If not, just let it be.
> Based on the commit description for dad8a3b3eaa0 ("igb, ixgbe:
> netdev_tx_reset_queue incorrectly called from tx init path"), yes, it
> hurts.  I don't know if it hurts enough to justify holding up this
> patch until dad8a3b3eaa0 hits mainline.
>
> |                            this sort of works in most cases except
> | when the number of real tx queues changes. When the number of real
> | tx queues changes netdev_tx_reset_queue() only gets called on the
> | new number of queues so when we reduce the number of queues we risk
> | triggering the watchdog timer and repeated device resets.
> |
> | So this is not only a cosmetic issue but causes real bugs. For
> | example enabling/disabling DCB or FCoE in ixgbe will trigger this.
I'm fairly certain we really shouldn't make the changes to igb.  I would
say to just modify the existing patch by just dropping the igb portion
of it and it would be fine.

Thanks,

Alex
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