[E1000-devel] ARM support for igb driver

[Arnd Bergmann]

On Tuesday 06 May 2014 17:24:33 Lucas Stach wrote:
> Am Dienstag, den 06.05.2014, 17:18 +0200 schrieb Arnd Bergmann:
> > On Monday 05 May 2014, Alexander Duyck wrote:
> > > Glad to hear that this is working on your ARM platform as expected.
> > > 
> > > I believe the issue Shiv is having is due to a problem with the specific
> > > platform as the IGB device is reporting a Data Link Protocol error via
> > > AER and I believe this is what is causing his platform issues.  On
> > > enabling BME the device is likely signalling a Fatal Error message in
> > > response to the DLP error.  The original error he was seeing was:
> > > 
> > > Unhandled fault: imprecise external abort (0x1406) at 0x00000000
> > 
> > This isn't too uncommon. There are a couple of traditional PCI host drivers
> > that register an imprecise external abort handler to catch this and
> > then look at the host controller registers.
> > 
> > Out of the pcie hosts, only drivers/pci/host/pci-imx6.c catches
> > this error, but it then goes on to ignore it, not even printing
> > a message about it.
> > 
> I think this handler is mostly there to handle the imprecise external
> abort happening on DW pcie IP if the bus scan tries to access an
> non-existent device. That's why it silently ignores this error.

That sounds rather dangerous, the driver should probably check for
the particular condition it tries to avoid and print a debug message
in that case, or halt the machine if finds any unknown error, to
prevent propagation of incorrect data.

	Arnd