Re: mlx4 BUG_ON in probe path

[Yishai Hadas]

On 11/16/2016 8:25 PM, Bjorn Helgaas wrote:
> Hi Yishai,
>
> Johannes has been working on an mlx4 initialization problem on an
> IBM x3850 X6.  The underlying problem is a PCI core issue -- we're
> setting RCB in the Mellanox device, which means it thinks it can
> generate 128-byte Completions, even though the Root Port above it
> can't handle them.  That issue is
> https://bugzilla.kernel.org/show_bug.cgi?id=187781
>
> The machine crashed when this happened, apparently not because of any
> error reported via AER, but because mlx4 contains a BUG_ON, probably
> the one in mlx4_enter_error_state().
>
> That one happens if pci_channel_offline() returns false.  Is this
> telling us about a problem in PCI error handling, or is it just a case
> where mlx4 isn't as smart as it could be?

Yes, we expect at that step a problem/bug in the PCI layer that should 
be fixed (e.g. reporting online but really is offline, etc.), can you 
please evaluate and confirm that ?