Re: possible bug regarding pciehp

[Greg KH <greg@kroah.com>]

On Fri, Sep 04, 2015 at 09:54:18AM +0200, Tormen wrote:
> On 09/02/2015 05:27 PM, Greg KH wrote:
> > On Wed, Sep 02, 2015 at 04:35:49PM +0200, Tormen wrote:
> >> Hi,
> >>
> >> I am contacting you, hoping that either you can maybe help
> >> or you know someone who can help :)
> >>
> >> I opened a bug related to the tg3 driver when hot-plugging via pciehp:
> >> https://bugzilla.kernel.org/show_bug.cgi?id\x100191
> >>
> >> I am desperate because :
> >> 	(a) there is also a brcmfmac related driver.
> >> So both wireless and wired internet have problems:
> >> 	https://bugzilla.kernel.org/show_bug.cgi?id\x100201
> >> 	(b) there was no input by anybody so far. Maybe because I wrongly
> >> categorized the tg3 bug ?
> >>
> >> The bug is related to Broadcom tg3 driver and the pciehp hotplug framework.
> >> In order to sort out where the problem(s) lies, I wanted to kindly ask
> >> you if you could have a look at the bug :
> >> https://bugzilla.kernel.org/show_bug.cgi?id\x100191
> >> ?
> >> And/or if you could help me figuring out if pciehp is causing this
> >> problem and/or if tg3 is to blame.
> > 
> > Odds are neither are the issue, this is a thunderbolt problem.  Make
> > sure you have enabled thunderbolt properly in your kernel if you want
> > hot-add of a device to work.
> >
> > I think the code has only been tested on older macbooks, changes might
> > be needed for newer ones given that Apple's thunderbolt controller is
> > "special" (i.e. doesn't follow the specification.)
> >
> > good luck!
> >
> > greg k-h
> >
> 
> Thanks a lot for your feedback !
> 
> Is "the code" that you are referring to the thunderbolt kernel module ?

Yes.

> The kernel I am using uses:
> CONFIG_THUNDERBOLT=m -- The module will be called thunderbolt.
> But when I boot-up with the plugged network device, lsmod does not show
> thunderbolt.

Have you loaded that module?  Please do so:
	modprobe thunderbolt

> So not sure how I can check further if thunderbolt is properly in my kernel?
> Or is it possible that I would need to load the thunderbolt module
> manually in order to make hotplug work?

Maybe.

> When the network driver is loaded it seems to connect as a "PCI Express"
> device:
> 	tg3 0000:0a:00.0 eth0: Tigon3 [partno(BCM957762) rev 57766000] (PCI
> Express)

That's separate from the thunderbolt controller.

> When I unplug the adapter the first thing appearing in dmesg is pciehp:
> [  210.992938] usb 1-2: USB disconnect, device number 4
> [ 1557.453818] pciehp 0000:06:03.0:pcie24: slot(3-2): Link Down event
> [ 1557.453870] pciehp 0000:06:03.0:pcie24: Cannot remove display device
> 0000:08:00.0
> [ 1557.509812] pciehp 0000:06:03.0:pcie24: Card not present on Slot(3-2)
> [ 1558.721344] tg3 0000:0a:00.0: tg3_abort_hw timed out, TX_MODE_ENABLE
> will not clear MAC_TX_MODEÿffffff
> [ 1558.934601] pciehp 0000:09:00.0:pcie24: unloading service driver pciehp
> [ 1558.935366] pciehp 0000:09:00.0:pcie24: Timeout on hotplug command
> 0x1038 (issued 1557532 msec ago)
> [ 1558.943460] pci_bus 0000:0a: busn_res: [bus 0a] is released
> [ 1558.958426] pci_bus 0000:09: busn_res: [bus 09-0a] is released
> [ 1558.958432] acpiphp: Slot [1] unregistered
> [ 1558.958451] acpiphp: Slot [2-1] unregistered
> [ 1558.958464] acpiphp: Slot [3-1] unregistered
> [ 1558.958475] acpiphp: Slot [4-1] unregistered
> [ 1558.958486] acpiphp: Slot [5-1] unregistered
> 
> But I am not a kernel, pciehp, thunderbolt specialist :(
> 
> How can I determine why the pciehp hotplug command 0x1038 timed out ?

No idea, sorry, this is very odd hardware that doesn't follow any spec.
Try emailing the author of the thunderbolt code, they should be able to
help you out more.

good luck,

greg k-h