On Tue, 30 Aug 2016, Richard van der Hoff wrote: > I have a USB-3.1 dock; sometimes I see a kernel panic when I unplug it, > which hangs the entire system. It appears that the first unplug is > successful; the second one normally triggers a crash. > > The situation is complicated by the fact that this USB bridge is behind > a chain of PCI bridges, which appear to power down when nothing is > plugged into the USB-C port. > > Greg K-H hinted via Bugzilla that this might be an area which is already > under development, in which case, apologies for the noise; but I'd be > interested in understanding a bit more about the problem, in any case. > > > The diagnostics below were all collected on kernel 4.7.0. > > The start of the panic, as captured over a serial console, is as follows: > > [ 44.010232] BUG: unable to handle kernel NULL pointer dereference at > (null) > [ 44.010274] IP: [<ffffffff81630316>] usb_hc_died+0x16/0xc0 > [ 44.010292] PGD 0 > [ 44.010300] Oops: 0000 [#1] SMP > [ 44.010310] Modules linked in: xt_CHECKSUM iptable_mangle > ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat > nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT > nf_reject_ipv4 > > ... and that's as far as it gets. Please try applying the patch at the bottom of this email: http://marc.info/?l=linux-usb&m=147195533502706&w=2 There's a good chance it will fix your problem. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
