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

[Johan Hovold]

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.

Johan