Re: [PATCH AUTOSEL for 4.14 19/60] Bluetooth: avoid silent hci_bcm ACPI PM regression

[alexander . levin]

On Wed, Dec 13, 2017 at 03:05:59PM +0100, Johan Hovold wrote:
>On Wed, Dec 13, 2017 at 01:37:26PM +0000, alexander.levin@xxxxxxxxxxx wrote:
>> On Wed, Dec 13, 2017 at 09:14:29AM +0100, Johan Hovold wrote:
>> >On Wed, Dec 13, 2017 at 01:55:14AM +0000, alexander.levin@xxxxxxxxxxx wrote:
>> >> From: Johan Hovold <johan@xxxxxxxxxx>
>> >>
>> >> [ Upstream commit 4294625e029028854596865be401b9c5c1f906ef ]
>> >>
>> >> The hci_bcm platform-device hack which was used to implement
>> >> power management for ACPI devices is being replaced by a
>> >> serial-device-bus implementation.
>> >>
>> >> Unfortunately, when the corresponding change to the ACPI code lands (a
>> >> change that will stop enumerating and registering the serial-device-node
>> >> child as a platform device) PM will break silently unless serdev
>> >> TTY-port controller support has been enabled. Specifically, hciattach
>> >> (btattach) would still succeed, but power management would no longer
>> >> work.
>> >
>> >This one is not needed in stable, which does not have the above
>> >mentioned ACPI change [ e361d1f85855 ("ACPI / scan: Fix enumeration for
>> >special UART devices") ].
>> >
>> >The Fixes and stable-CC tags were left out on purpose.
>>
>> Thanks Johan, I'll remove it.
>>
>> The Fixes tag should probably be there, as on it's own it does not
>> indicate a patch should go into stable, and we have tools to prevent
>> us from applying commits that "Fixes:" something which is not in the
>> tree.
>
>But that's the point; this patch was applied before the patch which
>might otherwise have ended up causing a regression. There was no commit
>id to use for a Fixes tag, and it did not fix anything when it was
>applied; its purpose was to avoid future breakage.

Gotcha, thanks!

-- 

Thanks,
Sasha