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Date: Wed, 14 Oct 2009 21:11:03 +0200
From: Wolfgang Grandegger <wg@grandegger.com>
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To: Grant Likely <grant.likely@secretlab.ca>
Subject: Re: [PATCH v2] net/fec_mpc52xx: Fix kernel panic on FEC error
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Cc: John Bonesio <bones@secretlab.ca>, netdev@vger.kernel.org,
	linuxppc-dev@lists.ozlabs.org, davem@davemloft.net
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Grant Likely wrote:
> From: John Bonesio <bones@secretlab.ca>
> 
> The MDIO bus cannot be accessed at interrupt context, but on an FEC
> error, the fec_mpc52xx driver reset function also tries to reset the
> PHY.  Since the error is detected at IRQ context, and the PHY functions
> try to sleep, the kernel ends up panicking.
> 
> Resetting the PHY on an FEC error isn't even necessary.  This patch
> solves the problem by removing the PHY reset entirely.

There is also no need to free and re-allocate the RX buffers in
mpc52xx_fec_reset().

Wolfgang.