Re: Linux v5.5 serious PCI bug

[mika.westerberg@xxxxxxxxxxxxxxx]

On Mon, Dec 09, 2019 at 12:34:04PM +0000, Nicholas Johnson wrote:
> Hi,
> 
> I have compiled Linux v5.5-rc1 and thought all was good until I 
> hot-removed a Gigabyte Aorus eGPU from Thunderbolt. The driver for the 
> GPU was not loaded (blacklisted) so the crash is nothing to do with the 
> GPU driver.
> 
> We had:
> - kernel NULL pointer dereference
> - refcount_t: underflow; use-after-free.
> 
> Attaching dmesg for now; will bisect and come back with results.

Looks like something related to iommu. Does it work if you disable it?
(intel_iommu=off in the command line).