Re: OHCI unplug kernel crash in kernel 4.3, 4.4 and 4.5

[Alan Stern]

On Sun, 28 Feb 2016, Greg KH wrote:

> On Sun, Feb 28, 2016 at 11:04:03AM -0800, Greg KH wrote:
> > On Sun, Feb 28, 2016 at 10:24:32AM +0100, Stefani Seibold wrote:
> > > I still reported this bug 6 Weeks ago... and i checked it know with the
> > > current kernel 4.5.0-rc5. The bug is yet not fixed.
> > > 
> > > A unplug of an USB 1.0 OHCI controller express card will result in a
> > > kernel crash. The express card is attached via thunderbolt and a sonnet
> > > express card to thunderbolt adapter. The computer hangs after the
> > > unplug, only a power down fix the situation.
> > > 
> > > This is the kernel log of a kernel 4.4 via netconsole:
> > 
> > Can you duplicate this without the nvidia driver loaded?
> 
> Oh, and without virtualbox, that is a horrid mess of total crap, NEVER
> trust that code to do anything correctly.  I'm totally amazed that it
> works at all, and it turns out, often times it really doesn't...

If the problem still occurs, please apply the diagnostic patch below
and post the resulting log messages.

Alan Stern



Index: usb-4.x/drivers/iommu/intel-iommu.c
===================================================================
--- usb-4.x.orig/drivers/iommu/intel-iommu.c
+++ usb-4.x/drivers/iommu/intel-iommu.c
@@ -2270,8 +2270,11 @@ static inline void unlink_domain_info(st
 	assert_spin_locked(&device_domain_lock);
 	list_del(&info->link);
 	list_del(&info->global);
-	if (info->dev)
+	if (info->dev) {
+		dev_info(info->dev, "unlink_domain_info\n");
+		dump_stack();
 		info->dev->archdata.iommu = NULL;
+	}
 }
 
 static void domain_remove_dev_info(struct dmar_domain *domain)