RE: [PATCH 4.4 009/115] Bluetooth: btusb: driver to enable the usb-wakeup feature

From: Ghorai, Sukumar
Date: Thu Dec 21 2017 - 13:52:42 EST

>> Linus' tree is broken in 2 ways:
>> 1. It includes this patch:
>> "Bluetooth: btusb: fix QCA Rome suspend/resume"
>> which is wrong, and we're on our way to reverting it upstream and
>> backporting that to -stable.
>> 2. It includes $subject patch. I'm not quite so sure, but I believe
>> it's not 100% "wrong"; it's just tougher for user space to deal with,
>> since now by default, all sorts of BT devices are set to be wakeup
>> sources. We can account for that in user space by being more careful
>> with initiating BT activity before suspend, but we don't currently do
>> that (at least not with the BlueZ in ChromeOS).
>> A related portion of this problem is that we briefly thought that this
>> patch resolved regressions with 1. In the end, it might mask some, but
>> it does not actually fix the problem. But then, you only included this
>> patch because somebody suggested it could resolve 1...
>> In the end, I'd say that #2 never belonged in -stable at all, and #1
>> was just "buggy" (so we're reverting it and letting the revert trickle
>> into -stable). I'm not sure I have a strong reason to revert #2
>> upstream, but I think I have an argument for not including it in
>> -stable.
>> I'm not sure what you mean by "bug-compatible"; if I wanted to use a
>> buggy kernel, I'd use Linus' tree :)
>> Or as I think I understand your point: the key point is that #2 might
>> not be actually a "bug", but a feature that user space has to be more
>> careful with. That may be a candidate for mainline, but not for
>> -stable, as I understand the current rules.
>I absolutely agree with Brian here. #2, or commit a0085f2510e8 ("Bluetooth:
>btusb: driver to enable the usb-wakeup feature") does not fix a bug, was not
>tagged for stable, and should not have been applied to stable releases in the first
>place. That it has a potential to cause trouble is not even relevant here.

Bug: platform can't wake using LE mouse/ keyboatd or any other LE I/O device
I feel we need to fix the other issue like S3 test fail, if any. And one of the other day
we need all of them - wakeup using LE mouse, ..