From: "Keller, Jacob E" <jacob.e.keller@intel•com>
To: "gpiccoli@linux•vnet.ibm.com" <gpiccoli@linux•vnet.ibm.com>,
"intel-wired-lan@lists•osuosl.org"
<intel-wired-lan@lists•osuosl.org>,
"Kirsher, Jeffrey T" <jeffrey.t.kirsher@intel•com>,
"alexander.duyck@gmail•com" <alexander.duyck@gmail•com>
Cc: "netdev@vger•kernel.org" <netdev@vger•kernel.org>,
"Fujinaka, Todd" <todd.fujinaka@intel•com>
Subject: Re: [PATCH net v2] igb: re-assign hw address pointer on reset after PCI error
Date: Fri, 2 Dec 2016 16:41:59 +0000 [thread overview]
Message-ID: <1480696918.16244.2.camel@intel.com> (raw)
In-Reply-To: <58416F5C.20602@linux.vnet.ibm.com>
On Fri, 2016-12-02 at 10:55 -0200, Guilherme G. Piccoli wrote:
> On 11/10/2016 04:46 PM, Guilherme G. Piccoli wrote:
> > Whenever the igb driver detects the result of a read operation
> > returns
> > a value composed only by F's (like 0xFFFFFFFF), it will detach the
> > net_device, clear the hw_addr pointer and warn to the user that
> > adapter's
> > link is lost - those steps happen on igb_rd32().
> >
> > In case a PCI error happens on Power architecture, there's a
> > recovery
> > mechanism called EEH, that will reset the PCI slot and call
> > driver's
> > handlers to reset the adapter and network functionality as well.
> >
> > We observed that once hw_addr is NULL after the error is detected
> > on
> > igb_rd32(), it's never assigned back, so in the process of
> > resetting
> > the network functionality we got a NULL pointer dereference in both
> > igb_configure_tx_ring() and igb_configure_rx_ring(). In order to
> > avoid
> > such bug, this patch re-assigns the hw_addr value in the slot_reset
> > handler.
> >
> > Reported-by: Anthony H. Thai <ahthai@us•ibm.com>
> > Reported-by: Harsha Thyagaraja <hathyaga@in•ibm.com>
> > Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux•vnet.ibm.com>
> > ---
> > drivers/net/ethernet/intel/igb/igb_main.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/intel/igb/igb_main.c
> > b/drivers/net/ethernet/intel/igb/igb_main.c
> > index edc9a6a..136ee9e 100644
> > --- a/drivers/net/ethernet/intel/igb/igb_main.c
> > +++ b/drivers/net/ethernet/intel/igb/igb_main.c
> > @@ -7878,6 +7878,11 @@ static pci_ers_result_t
> > igb_io_slot_reset(struct pci_dev *pdev)
> > pci_enable_wake(pdev, PCI_D3hot, 0);
> > pci_enable_wake(pdev, PCI_D3cold, 0);
> >
> > + /* In case of PCI error, adapter lose its HW
> > address
> > + * so we should re-assign it here.
> > + */
> > + hw->hw_addr = adapter->io_addr;
> > +
> > igb_reset(adapter);
> > wr32(E1000_WUS, ~0);
> > result = PCI_ERS_RESULT_RECOVERED;
> >
>
> Ping?
>
> Sorry to annoy, any news on this?
> Thanks in advance!
>
> Cheers,
>
>
> Guilherme
>
This seems reasonable. It's similar to what fm10k driver does under
this circumstance.
Thanks,
Jake
next prev parent reply other threads:[~2016-12-02 16:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-10 18:46 [PATCH net v2] igb: re-assign hw address pointer on reset after PCI error Guilherme G. Piccoli
2016-12-02 12:55 ` Guilherme G. Piccoli
2016-12-02 16:41 ` Keller, Jacob E [this message]
2016-12-13 20:51 ` [Intel-wired-lan] " Brown, Aaron F
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