On 12/6/19 1:57 PM, Marek Marczykowski-Górecki wrote:
On Fri, Dec 06, 2019 at 03:50:58PM +0900, Suwan Kim wrote:
On Fri, Dec 06, 2019 at 04:24:06AM +0100, Marek Marczykowski-Górecki wrote:
Hello,
I've hit an issue with recent 4.19 and 5.4 kernels. In short: if I
connect Yubikey 4 and use its CCID interface (for example `ykman oath
list` command), the client side hangs (100% reliably). After 60s I get a
message that a CPU hangs waiting for a spinlock (see below).
I've bisected it to a ea44d190764b4422af ("usbip: Implement SG support
to vhci-hcd and stub driver") commit. Which indeed is also backported to
4.19.
Any idea what is going on here? I can easily provide more information,
if you tell me how to get it.
Hi,
Thanks for reporting. Could you turn on lockdep and USBIP_DEBUG
in kernel config and send dmesg log? It will be helpful to figure
out lock dependency in vhci_hcd.
Hmm, I've tried, but I don't see much more information there (see
below). I've just enabled PROVE_LOCKING and USBIP_DEBUG. Do I need to do
anything more, like some boot option?
Also, this one (as the previous one) is from 4.19.84. Interestingly, on
4.19.87 I don't get the message at all.
Hmm, I've done also another test: got 4.19.84 with "usbip: Implement SG
support to vhci-hcd and stub driver" reverted and it still hangs...
I'm going for another bisect round (4.19.81 works, 4.19.84 doesn't).
Does 4.19.82 work?
thanks,
-- Shuah
