[SRU] [B/D/E/Unstable/OEM-B/OEM-OSP1-B] [PATCH 0/2] Fix unusable USB hub on Dell TB16 after S3

Kai-Heng Feng kai.heng.feng at canonical.com
Thu Dec 5 17:05:25 UTC 2019

BugLink: https://bugs.launchpad.net/bugs/1855312

Sometimes USB hub on Dell TB16 stop working after S3.

Attempt to power cycle USB device when a it's stuck at eSS.Disabled
state, it's basically not recoverable. 

After applying the patch, USB ports and USB ethernet are still working
after 100 times S3 stress test.

[Regression Potential]
Low. This is a last resort attempt, in most cases this code path won't
be reached.

Kai-Heng Feng (2):
  UBUNTU: SAUCE: USB: core: Make port power cycle a seperate helper
  UBUNTU: SAUCE: USB: core: Attempt power cycle port when it's in
    eSS.Disabled state

 drivers/usb/core/hub.c  | 46 +++++++++++++++++++++++++++++++++++------
 drivers/usb/core/hub.h  |  3 +--
 drivers/usb/core/port.c |  4 ++--
 3 files changed, 43 insertions(+), 10 deletions(-)


More information about the kernel-team mailing list