Re: [PATCH v2 1/5] ALSA: xen-front: Introduce Xen para-virtualized sound frontend driver

[Oleksandr Andrushchenko]

On 04/16/2018 03:25 PM, Juergen Gross wrote:
> On 16/04/18 08:24, Oleksandr Andrushchenko wrote:
> > From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
> >
> > Introduce skeleton of the para-virtualized Xen sound
> > frontend driver.
> >
> > Initial handling for Xen bus states: implement
> > Xen bus state machine for the frontend driver according to
> > the state diagram and recovery flow from sound para-virtualized
> > protocol: xen/interface/io/sndif.h.
> >
> > Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
> Only one minor nit (see below). With that addressed (or fixed when
> committing):
will fix
> Reviewed-by: Juergen Gross <jgross@xxxxxxxx>
Thank you
> Juergen
>
> > ---
> >   sound/Kconfig             |   2 +
> >   sound/Makefile            |   2 +-
> >   sound/xen/Kconfig         |  10 +++
> >   sound/xen/Makefile        |   5 ++
> >   sound/xen/xen_snd_front.c | 196 ++++++++++++++++++++++++++++++++++++++++++++++
> >   sound/xen/xen_snd_front.h |  18 +++++
> >   6 files changed, 232 insertions(+), 1 deletion(-)
> >   create mode 100644 sound/xen/Kconfig
> >   create mode 100644 sound/xen/Makefile
> >   create mode 100644 sound/xen/xen_snd_front.c
> >   create mode 100644 sound/xen/xen_snd_front.h
> >
> > diff --git a/sound/xen/xen_snd_front.c b/sound/xen/xen_snd_front.c
> > new file mode 100644
> > index 000000000000..f406a8f52c51
> > --- /dev/null
> > +++ b/sound/xen/xen_snd_front.c
> > @@ -0,0 +1,196 @@
> > +static void sndback_changed(struct xenbus_device *xb_dev,
> > +			    enum xenbus_state backend_state)
> > +{
> > +	struct xen_snd_front_info *front_info = dev_get_drvdata(&xb_dev->dev);
> > +	int ret;
> > +
> > +	dev_dbg(&xb_dev->dev, "Backend state is %s, front is %s\n",
> > +		xenbus_strstate(backend_state),
> > +		xenbus_strstate(xb_dev->state));
> > +
> > +	switch (backend_state) {
> > +	case XenbusStateReconfiguring:
> > +		/* fall through */
> > +	case XenbusStateReconfigured:
> > +		/* fall through */
> > +	case XenbusStateInitialised:
> > +		/* fall through */
> > +		break;
> > +
> > +	case XenbusStateInitialising:
> > +		/* recovering after backend unexpected closure */
> > +		sndback_disconnect(front_info);
> > +		break;
> > +
> > +	case XenbusStateInitWait:
> > +		/* recovering after backend unexpected closure */
> > +		sndback_disconnect(front_info);
> > +
> > +		ret = sndback_initwait(front_info);
> > +		if (ret < 0)
> > +			xenbus_dev_fatal(xb_dev, ret, "initializing frontend");
> > +		else
> > +			xenbus_switch_state(xb_dev, XenbusStateInitialised);
> > +		break;
> > +
> > +	case XenbusStateConnected:
> > +		if (xb_dev->state != XenbusStateInitialised)
> > +			break;
> > +
> > +		ret = sndback_connect(front_info);
> > +		if (ret < 0)
> > +			xenbus_dev_fatal(xb_dev, ret, "initializing frontend");
> > +		else
> > +			xenbus_switch_state(xb_dev, XenbusStateConnected);
> > +		break;
> > +
> > +	case XenbusStateClosing:
> > +		/*
> > +		 * in this state backend starts freeing resources,
> > +		 * so let it go into closed state first, so we can also
> > +		 * remove ours
> > +		 */
> Please start the sentence with a capital letter and end it with a
> full stop.
>
>
> Juergen