Public bug reported:
Starting with Ubuntu kernel 3.13.0-44.73, the system spuriously reboots
instead of powering off. Kernels up to 3.13.0-43.72 are not affected.
The problem is 100% reproducible. It has also been mentioned in
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1346269/comments/15
but that bug report was originally about different hardware (Lynx Point,
not Lynx Point-LP) and should not be hijacked to discuss the EliteBook
8x0. The same holds for bug #1320282.
Kernel 3.19.0-30 is also affected. The problem persists if the system is
booted with xhci_hcd.quirks=0x2000 (XHCI_SPURIOUS_REBOOT) but goes away
if one boots with xhci_hcd.quirks=0x40000 (XHCI_SPURIOUS_WAKEUP).
I've almost completed a bisection between 3.13.0-43.72 and 3.13.0-44.73.
The remaining commits include both "xhci: Switch only Intel Lynx Point-
LP ports to EHCI on shutdown." and "xhci: no switching back on non-ULT
Haswell", however both the hardware configuration (Lynx Point-LP,
8086:9c31) and the above mentioned tests with quirk bit settings
strongly suggest it's the latter commit that is at fault and that on
this particular hardware (ULT Haswell) one needs *both*
XHCI_SPURIOUS_REBOOT (automatically enabled by all the kernels I
mentioned) and XHCI_SPURIOUS_WAKEUP.
I have only intermittent access to an affected system and limited
interest in spending more time on this now that a workaround (run a
newer kernel with xhci_hcd.quirks=0x40000) is known. However, my
findings so far may be valuable to others.
A look at the current linux-stable source tree on git.kernel.org
suggests that the problem has yet to be addressed upstream (unless it's
fixed/masked by some other change elsewhere in the code; I haven't
actually tested the latest upstream kernel).
The output of lspci -vvvnn (not -vnvn, sorry; I hope it's good enough)
is attached.
We've tried BIOS revisions 1.30 and 1.33. (1.33 is the latest, and 1.30
was a critical update so anything older is probably not worth
supporting.)
** Affects: linux (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 trusty
** Attachment added: "lspci -vvvnn output on EliteBook 850 G1"
https://bugs.launchpad.net/bugs/1504003/+attachment/4488282/+files/lspci-vvvnn.log
--
You received this bug notification because you are a member of Ubuntu
Bugs, which is subscribed to Ubuntu.
https://bugs.launchpad.net/bugs/1504003
Title:
Regression: spurious wakeup on HP EliteBook 850 G1
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1504003/+subscriptions
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
