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

16 Apr 2018

On 16/04/18 08:24, Oleksandr Andrushchenko wrote:
...
From: Oleksandr Andrushchenko oleksandr_andrushchenko@epam.com
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@epam.com
Only one minor nit (see below). With that addressed (or fixed when
committing):
Reviewed-by: Juergen Gross jgross@suse.com
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

    