[SRU] [B/D/E/Unstable/OEM-B/OEM-OSP1-B] [PATCH 0/2] Fix unusable USB hub on Dell TB16 after S3
kleber.souza at canonical.com
Wed Dec 11 11:16:15 UTC 2019
On 2019-12-11 10:07, Kai-Heng Feng wrote:
>> 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
>>> 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(-)
>> 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.
Although you mentioned this code path is a last resort and won't be executed
in most of the cases, this touches the USB core code and the patches don't
look trivial. So I would like to get some more info about any regression
tests we have executed on other platforms other than the affected one.
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