Re: [PATCH net] bnx2x: Improve reliability in case of nested PCI errors

[David Miller <davem@davemloft.net>]

From: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>
Date: Fri, 22 Dec 2017 13:01:39 -0200

> While in recovery process of PCI error (called EEH on PowerPC arch),
> another PCI transaction could be corrupted causing a situation of
> nested PCI errors. Also, this scenario could be reproduced with
> error injection mechanisms (for debug purposes).
> 
> We observe that in case of nested PCI errors, bnx2x might attempt to
> initialize its shmem and cause a kernel crash due to bad addresses
> read from MCP. Multiple different stack traces were observed depending
> on the point the second PCI error happens.
> 
> This patch avoids the crashes by:
> 
>  * failing PCI recovery in case of nested errors (since multiple
>  PCI errors in a row are not expected to lead to a functional
>  adapter anyway), and by,
> 
>  * preventing access to adapter FW when MCP is failed (we mark it as
>  failed when shmem cannot get initialized properly).
> 
> Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>

Applied, thank you.