[PATCH 1/1] UBUNTU: SAUCE: USB: Disable USB2 LPM at shutdown

Seth Forshee seth.forshee at canonical.com
Fri Jun 14 20:26:34 UTC 2019

On Mon, Jun 10, 2019 at 03:21:41PM +0800, Kai-Heng Feng wrote:
> BugLink: https://bugs.launchpad.net/bugs/1757218
> The QCA Rome USB Bluetooth controller has several issues once LPM gets
> enabled:
> - Fails to get enumerated in coldboot. [1]
> - Drains more power (~ 0.2W) when the system is in S5. [2]
> - Disappears after a warmboot. [2]
> The issue happens because the device lingers at LPM L1 in S5, so device
> can't get enumerated even after a reboot.
> Disable LPM at shutdown to solve the issue.
> [1] https://bugs.launchpad.net/bugs/1757218
> [2] https://patchwork.kernel.org/patch/10607097/

On this upstream thread you leak to some doubts are expressed about this
patch, followed by a promise to dig further into the problem but no
follow-up. What has transpired since then to verify that this patch is
1) safe and 2) not just papering over some other problem?


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