Re: [PATCH v2 9/9] Bluetooth: hci_bcm: Add (runtime)pm support to the serdev driver

On Mon, Oct 09, 2017 at 04:02:24PM +0200, Hans de Goede wrote:

Hi,

On 07-10-17 16:26, Johan Hovold wrote:

quoted

However, there are of course a couple of caveats. Once Frederic's ACPI
patches land, there will be no more platform child devices. Unless
serdev support is then compiled in, this means that PM will break
(silently). And if serdev is enabled, of course the tty class device is
gone and hciattach (btattach) will fail, but I guess everyone is aware
of that issue by now.

Should BT_HCIUART_BCM start depending on SERIAL_DEV_CTRL_TTYPORT (when
ACPI is enabled) to avoid such silent breakage once ACPI-support is
merged?

It seems that this was answered already in further discussions and
your recent patch to add a default y to SERIAL_DEV_CTRL_TTYPORT fixes
this, right ?

Only partially, as the serdev bus code could still be built as a module,
which would prevent SERIAL_DEV_CTRL_TTYPORT from being selected.

We could consider having BT_HCIUART_BCM depend on
SERIAL_DEV_CTRL_TTYPORT (or !ACPI || SERIAL_DEV_CTRL_TTYPORT) just to
avoid any hard-to-detect regressions.

Johan