Re: [PATCH net-next] bnx2: Close device if tx_timeout reset fails

[David Miller <davem@davemloft.net>]

From: "Michael Chan" <mchan@broadcom.com>
Date: Fri, 15 Jul 2011 09:53:58 -0700

> Based on original patch and description from Flavio Leitner <fbl@redhat.com>
> 
> When bnx2_reset_task() is called, it will stop,
> (re)initialize and start the interface to restore
> the working condition.
> 
> The bnx2_init_nic() calls bnx2_reset_nic() which will
> reset the chip and then calls bnx2_free_skbs() to free
> all the skbs.
> 
> The problem happens when bnx2_init_chip() fails because
> bnx2_reset_nic() will just return skipping the ring
> initializations at bnx2_init_all_rings(). Later, the
> reset task starts the interface again and the system
> crashes due a NULL pointer access (no skb in the ring).
> 
> To fix it, we call dev_close() if bnx2_init_nic() fails.
> One minor wrinkle to deal with is the cancel_work_sync()
> call in bnx2_close() to cancel bnx2_reset_task().  The
> call will wait forever because it is trying to cancel
> itself and the workqueue will be stuck.
> 
> Since bnx2_reset_task() holds the rtnl_lock() and checks
> for netif_running() before proceeding, there is no need
> to cancel bnx2_reset_task() in bnx2_close() even if
> bnx2_close() and bnx2_reset_task() are running concurrently.
> The rtnl_lock() serializes the 2 calls.
> 
> We need to move the cancel_work_sync() call to
> bnx2_remove_one() to make sure it is canceled before freeing
> the netdev struct.
> 
> Signed-off-by: Michael Chan <mchan@broadcom.com>
> Signed-off-by: Matt Carlson <mcarlson@broadcom.com>

Applied, thanks everyone.