Commit Graph

11 Commits

Author SHA1 Message Date
Takashi Iwai 3ac14b3960 ALSA: xen: Use standard pcm_format_to_bits() for ALSA format bits
The open codes with the bit shift in xen_snd_front_alsa.c give sparse
warnings as the PCM format type is with __bitwise.
There is already a standard macro to get the format bits, so let's use
it instead.

This fixes sparse warnings like:
  sound/xen/xen_snd_front_alsa.c:191:47: warning: restricted snd_pcm_format_t degrades to integer

Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-27 09:05:34 +02:00
Dan Carpenter 0d5bcfc997 ALSA: xen-front: fix a loop timeout
We want the loop to exit when "to" is set to zero, but in the current
code it's set to -1.  Also I tweaked the indenting so it doesn't look
like we're passing "--to" to xenbus_read_unsigned().

Fixes: cc3196ae19 ("ALSA: xen-front: Introduce Xen para-virtualized sound frontend driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-31 09:11:03 +02:00
Dan Carpenter e46dcbb17d ALSA: xen-front: freeing an error pointer
kfree() doesn't accept error pointers so I've set "str" to NULL on these
paths.

Fixes: fd3b36045c ("ALSA: xen-front: Read sound driver configuration from Xen store")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-30 13:19:45 +02:00
Arnd Bergmann 4c0eaac716 ALSA: xen: ensure nul-terminated device name
gcc-8 warns that pcm_instance->name is not necessarily terminated correctly
if the input is more than 80 characters long or lacks a termination byte
itself:

In function 'strncpy',
    inlined from 'cfg_device' at sound/xen/xen_snd_front_cfg.c:399:3,
    inlined from 'xen_snd_front_cfg_card' at sound/xen/xen_snd_front_cfg.c:509:9:
include/linux/string.h:254:9: error: '__builtin_strncpy' specified bound 80 equals destination size [-Werror=stringop-truncation]
  return __builtin_strncpy(p, q, size);

Using strlcpy() instead of strncpy() makes this a bit safer.

Fixes: fd3b36045c ("ALSA: xen-front: Read sound driver configuration from Xen store")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-29 08:27:54 +02:00
Colin Ian King 014cea591a ALSA: xen-front: fix unsigned error check on return from to_sndif_format
The negative error return from the call to to_sndif_format is being
assigned to an unsigned 8 bit integer and hence the check for a negative
value is always going to be false.  Fix this by using ret as the error
return and hence the negative error can be detected and assign
the u8 sndif_format to ret if there is no error.

Detected by CoverityScan, CID#1469385 ("Unsigned compared against 0")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamoccchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-28 11:30:33 +02:00
Colin Ian King 3d62461737 ALSA: xen-front: remove redundant error check on ret
The error for a -ve value in ret is redundant as all previous
assignments to ret have an associated -ve check and hence it
is impossible for ret to be less that zero at the point of the
check.  Remove this redundant error check.

Detected by CoveritScan, CID#1469407 ("Logically Dead code")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-28 11:28:44 +02:00
Oleksandr Andrushchenko 1cee559351 ALSA: xen-front: Implement ALSA virtual sound driver
Implement essential initialization of the sound driver:
  - introduce required data structures
  - handle driver registration
  - handle sound card registration
  - register sound driver on backend connection
  - remove sound driver on backend disconnect

Initialize virtual sound card with streams according to the
Xen store configuration.

Implement ALSA driver operations including:
  - manage frontend/backend shared buffers
  - manage Xen bus event channel states

Implement requests from front to back for ALSA
PCM operations.
  - report ALSA period elapsed event: handle XENSND_EVT_CUR_POS
    notifications from the backend when stream position advances
    during playback/capture. The event carries a value of how
    many octets were played/captured at the time of the event.
  - implement explicit stream parameter negotiation between
    backend and frontend: handle XENSND_OP_HW_PARAM_QUERY request
    to read/update configuration space for the parameter given:
    request passes desired parameter interval and the response to
    this request returns min/max interval for the parameter to be used.

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-16 12:59:57 +02:00
Oleksandr Andrushchenko d6e0fbb82e ALSA: xen-front: Implement handling of shared buffers
Implement shared buffer handling according to the
para-virtualized sound device protocol at xen/interface/io/sndif.h:
  - manage buffer memory
  - handle granted references
  - handle page directories

[ Fixed missing linux/kernel.h inclusion -- tiwai ]

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-16 12:59:50 +02:00
Oleksandr Andrushchenko 788ef64a2c ALSA: xen-front: Implement Xen event channel handling
Handle Xen event channels:
  - create for all configured streams and publish
    corresponding ring references and event channels in Xen store,
    so backend can connect
  - implement event channels interrupt handlers
  - create and destroy event channels with respect to Xen bus state

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-16 12:58:41 +02:00
Oleksandr Andrushchenko fd3b36045c ALSA: xen-front: Read sound driver configuration from Xen store
Read configuration values from Xen store according
to xen/interface/io/sndif.h protocol:
  - introduce configuration structures for different
    components, e.g. sound card, device, stream
  - read PCM HW parameters, e.g rate, format etc.
  - detect stream type (capture/playback)
  - read device and card parameters

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-16 12:58:39 +02:00
Oleksandr Andrushchenko cc3196ae19 ALSA: xen-front: Introduce Xen para-virtualized sound frontend driver
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>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-16 12:58:36 +02:00