Re: double-freed irq when suspending with Thinkpad Thunderbolt Dock attached

[Mathias Nyman <mathias.nyman@linux.intel.com>]

On 9.4.2020 19.23, Damien Riegel wrote:
> Hi,
> 
> 
> I have a setup with a Thinkpad X1 Carbon Gen 6 with a Thinkpad
> Thunderbolt 3 Dock attached to it. The issue is not exhibited when the
> dock is not attached to the laptop.
> 
> Most of the time, it fails to resume from a suspend-to-disk. The system
> hangs and logs are not flushed to disk so I don't have more details.
> 
> But sometimes (maybe 1 out of 20 times), it manages to resume and there
> are double-freed irq errors, as shown in the following logs. As far as I
> am concerned, the laptop is running fine on resume, but maybe this can
> give a hint to where the issue causing the hang is.
> 
> I'm Ccing linux-usb and linux-pci as I couldn't tell which subsystem is
> responsible.
> 
> 
> Thanks,
> Damien

xhci driver resume tries to reset and reinitialize everything in this case,
shalting and resetting the host, and freeing irq and memory before
reallocating everything.
xhci driver resume doesn't notice the PCI device was already gone at this point,
and will double free the irq.

There is a patch in 5.7-rc1 that checks if xHC is accessible in resume, and should
prevent the double free.

72ae194704da xhci: bail out early if driver can't accress host in resume

Does it work for you?

-Mathias