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From: David Miller <davem@davemloft.net>
To: grant.likely@secretlab.ca
Cc: a.llano@ziv.es, netdev@vger.kernel.org, linuxppc-dev@ozlabs.org
Subject: Re: [PATCH/REPOST] net/mpc5200: Fix locking on fec_mpc52xx driver
Date: Tue, 08 Dec 2009 20:28:38 -0800 (PST)	[thread overview]
Message-ID: <20091208.202838.78052287.davem@davemloft.net> (raw)
In-Reply-To: <20091205043015.28041.19288.stgit@angua>

From: Grant Likely <grant.likely@secretlab.ca>
Date: Fri, 04 Dec 2009 21:33:13 -0700

> Fix the locking scheme on the fec_mpc52xx driver.  This device can
> receive IRQs from three sources; the FEC itself, the tx DMA, and the
> rx DMA.  Mutual exclusion was handled by taking a spin_lock() in the
> critical regions, but because the handlers are run with IRQs enabled,
> spin_lock() is insufficient and the driver can end up interrupting
> a critical region anyway from another IRQ.
> 
> Asier Llano discovered that this occurs when an error IRQ is raised
> in the middle of handling rx irqs which resulted in an sk_buff memory
> leak.

I'll apply this fix.

But, longer term, it's a thousand times easier and more efficient to
move the processing of these interrupts into softirq context.

  reply	other threads:[~2009-12-09  4:28 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-12-05  4:33 [PATCH/REPOST] net/mpc5200: Fix locking on fec_mpc52xx driver Grant Likely
2009-12-09  4:28 ` David Miller [this message]
2009-12-09  5:16   ` Grant Likely

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