[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]

> On Dec 11, 2019, at 17:03, Kleber Souza <kleber.souza at canonical.com> wrote:
> 
> On 2019-12-05 18:05, Kai-Heng Feng wrote:
>> BugLink: https://bugs.launchpad.net/bugs/1855312
>> 
>> [Impact]
>> Sometimes USB hub on Dell TB16 stop working after S3.
>> 
>> [Fix]
>> Attempt to power cycle USB device when a it's stuck at eSS.Disabled
>> state, it's basically not recoverable. 
>> 
>> [Test]
>> 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
>>    function
>>  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(-)
>> 
> 
> Hi Kai-Heng,
> 
> The fix is targeted to Unstable so I assume this affects mainline as
> well. Are we going to try to upstream this fix?

Yes. I've been poking upstream many times but there's no response.
This fix is quite crucial to TB16 so we still need this in our kernel.

Kai-Heng

> 
> 
> Thanks,
> Kleber