On 23-02-18 04:12, Brian Norris wrote:
Hi Hans,

Sorry if I'm a little slow to follow up here. This hasn't been my
top priority...

On Mon, Feb 19, 2018 at 11:17:24AM +0100, Hans de Goede wrote:
On 16-02-18 18:59, Brian Norris wrote:
On Fri, Feb 16, 2018 at 01:10:20PM +0100, Hans de Goede wrote:
Ok, I've asked the reporter of:


Are you even sure that this reporter is seeing the original symptom at
all (BT loses power, and therefore firmware)? Their report shows them
running 4.15, which had this commit:

fd865802c66b Bluetooth: btusb: fix QCA Rome suspend/resume

which is admittedly completely broken. It breaks even perfectly working
BT/USB devices, like mine. That's where I first complained, and we got
this into 4.16-rc1:

7d06d5895c15 Revert "Bluetooth: btusb: fix QCA Rome suspend/resume"

Isn't it possible your reporter has no further problem, and none if this
is actually important to them? I'd just caution you to be careful before
assuming you need to add blacklist info for their DMI...

Thanks, that is a good question. His problems only started when I
enabled usb-autosuspend by default for btusb devices and he got things
working by adding "btusb.enable_autosuspend=n" on the kernel commandline,
so he was not hitting the firmware loading race introduced by
fd865802c66b and runtime suspend/resume is really broken for him.

Hmm? I'm not sure I completely follow here when you say "he was not
hitting the firmware loading race". If things were functioning fine with
system suspend (but not with autosuspend), then he's not seeing the
controller (quoting commit fd865802c66b) "losing power during suspend".

He was running a kernel with the original "fd865802c66b Bluetooth: btusb:
fix QCA Rome suspend/resume" commit, which fixes regular suspend for
devices which are "losing power during suspend", but does nothing for

He ran tests both with and without runtime-pm enabled with that same kernel
and he needed to disable runtime-pm to get working bluetooth.

So, that would suggest he could only be seeing the race (as I was), and
that his machine does not deserve a RESET_RESUME quirk?

I hope my above answer helps to clarify why I believe the quirk is
necessary on his machine.



Or maybe I'm really misunderstanding.

As I read it, you need to investigate who are the "numerous reported
instances" that generated commit fd865802c66b in the first place. That's
where this mess started, IIUC. >
But otherwise, yes, option 3 sounds OK. FWIW, my systems are ARM based
and don't have DMI data, so option 2 wouldn't work.

Right I think we all agree that the new plan now is to go back to
QCA behaving normally wrt (runtime) suspend/resume and then set the
USB-core RESET_RESUME quirk (which does not have the firmware
loading race) based on a DMI blacklist.

I only have the one report for which I will write a patch implementing
this new policy soonish. And Kai-Heng Feng has another report which
might even be the machine. I certainly would not be surprised if it
is another Lenovo machine.

It seems like you folks moved forward on that one. Thanks.


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