Commit Graph

16 Commits

Author SHA1 Message Date
Aiswarya Cyriac
ba00e413fa ALSA: virtio: Fix "Coverity: virtsnd_kctl_tlv_op(): Uninitialized variables" warning.
This commit fixes the following warning when building virtio_snd driver.

"
*** CID 1583619:  Uninitialized variables  (UNINIT)
sound/virtio/virtio_kctl.c:294 in virtsnd_kctl_tlv_op()
288
289     		break;
290     	}
291
292     	kfree(tlv);
293
vvv     CID 1583619:  Uninitialized variables  (UNINIT)
vvv     Using uninitialized value "rc".
294     	return rc;
295     }
296
297     /**
298      * virtsnd_kctl_get_enum_items() - Query items for the ENUMERATED element type.
299      * @snd: VirtIO sound device.
"

This warning is caused by the absence of the "default" branch in the
switch-block, and is a false positive because the kernel calls
virtsnd_kctl_tlv_op() only with values for op_flag processed in
this block.

Also, this commit unifies the cleanup path for all possible control
paths in the callback function.

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Signed-off-by: Aiswarya Cyriac <aiswarya.cyriac@opensynergy.com>
Reported-by: coverity-bot <keescook+coverity-bot@chromium.org>
Addresses-Coverity-ID: 1583619 ("Uninitialized variables")
Fixes: d6568e3de4 ("ALSA: virtio: add support for audio controls")
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20240216100643.688590-1-aiswarya.cyriac@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-02-16 15:01:31 +01:00
Anton Yakovlev
d6568e3de4 ALSA: virtio: add support for audio controls
Implementation of support for audio controls in accordance with the
extension of the virtio sound device specification [1] planned for
virtio-v1.3-cs01.

The device can announce the VIRTIO_SND_F_CTLS feature. If the feature is
negotiated, then an additional field appears in the configuration space:

  struct virtio_snd_config {
    ...
    /* number of available control elements */
    __le32 controls;
  };

The driver can send the following requests to manage audio controls:

  enum {
    ...
    /* control element request types */
    VIRTIO_SND_R_CTL_INFO = 0x0300,
    VIRTIO_SND_R_CTL_ENUM_ITEMS,
    VIRTIO_SND_R_CTL_READ,
    VIRTIO_SND_R_CTL_WRITE,
    VIRTIO_SND_R_CTL_TLV_READ,
    VIRTIO_SND_R_CTL_TLV_WRITE,
    VIRTIO_SND_R_CTL_TLV_COMMAND,
    ...
  };

And the device can send the following audio control event notification:

  enum {
    ...
    /* control element event types */
    VIRTIO_SND_EVT_CTL_NOTIFY = 0x1200,
    ...
  };

See additional details in [1].

[1] https://lists.oasis-open.org/archives/virtio-comment/202104/msg00013.html

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Signed-off-by: Aiswarya Cyriac <aiswarya.cyriac@opensynergy.com>
Link: https://lore.kernel.org/r/20240115133654.576068-2-aiswarya.cyriac@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-02-09 14:01:15 +01:00
Li RongQing
d62ccb59af ALSA: virtio: remove duplicate check if queue is broken
virtqueue_enable_cb() will call virtqueue_poll() which will check if
queue is broken at beginning, so remove the virtqueue_is_broken() call

Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Link: https://lore.kernel.org/r/20240124120834.49410-1-lirongqing@baidu.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-01-24 14:41:37 +01:00
Matias Ezequiel Vara Larsen
fe981e6756 ALSA: virtio: use ack callback
This commit uses the ack() callback to determine when a buffer has been
updated, then exposes it to guest.

The current mechanism splits a dma buffer into descriptors that are
exposed to the device. This dma buffer is shared with the user
application. When the device consumes a buffer, the driver moves the
request from the used ring to available ring.

The driver exposes the buffer to the device without knowing if the
content has been updated from the user. The section 2.8.21.1 of the
virtio spec states that: "The device MAY access the descriptor chains
the driver created and the memory they refer to immediately". If the
device picks up buffers from the available ring just after it is
notified, it happens that the content may be old.

When the ack() callback is invoked, the driver exposes only the buffers
that have already been updated, i.e., enqueued in the available ring.
Thus, the device always picks up a buffer that is updated.

For capturing, the driver starts by exposing all the available buffers
to device. After device updates the content of a buffer, it enqueues it
in the used ring. It is only after the ack() for capturing is issued
that the driver re-enqueues the buffer in the available ring.

Co-developed-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Signed-off-by: Matias Ezequiel Vara Larsen <mvaralar@redhat.com>
Link: https://lore.kernel.org/r/ZTjkn1YAFz67yfqx@fedora
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2023-10-27 11:25:07 +02:00
Michael S. Tsirkin
d9679d0013 virtio: wrap config->reset calls
This will enable cleanups down the road.
The idea is to disable cbs, then add "flush_queued_cbs" callback
as a parameter, this way drivers can flush any work
queued after callbacks have been disabled.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20211013105226.20225-1-mst@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-01-14 18:50:52 -05:00
Gustavo A. R. Silva
b38269ecd2 ALSA: virtio: Replace zero-length array with flexible-array member
There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

Also, make use of the struct_size() helper in kzalloc().

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20210929191504.GA337268@embeddedor
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-09-30 13:47:57 +02:00
Pierre-Louis Bossart
e861431303 ALSA: virtio: fix kernel-doc
make W=1 warning:

sound/virtio/virtio_ctl_msg.c:70: warning: expecting prototype for
virtsnd_ctl_msg_request(). Prototype was for
virtsnd_ctl_msg_response() instead

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210426213902.234711-1-pierre-louis.bossart@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-04-27 08:39:39 +02:00
Chen Huang
d91cbe83d3 ALSA: virtio: use module_virtio_driver() to simplify the code
module_virtio_driver() makes the code simpler by eliminating
boilerplate code.

Signed-off-by: Chen Huang <chenhuang5@huawei.com>
Reviewed-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Link: https://lore.kernel.org/r/20210408125429.1158703-1-chenhuang5@huawei.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-04-12 12:15:34 +02:00
Anton Yakovlev
575483e90a ALSA: virtio: introduce device suspend/resume support
All running PCM substreams are stopped on device suspend and restarted
on device resume.

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Link: https://lore.kernel.org/r/20210302164709.3142702-10-anton.yakovlev@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-03-07 09:08:39 +01:00
Anton Yakovlev
19325fedf2 ALSA: virtio: introduce PCM channel map support
Enumerate all available PCM channel maps and create ALSA controls.

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Link: https://lore.kernel.org/r/20210302164709.3142702-9-anton.yakovlev@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-03-07 09:08:20 +01:00
Anton Yakovlev
ca61a41f38 ALSA: virtio: introduce jack support
Enumerate all available jacks and create ALSA controls.

At the moment jacks have a simple implementation and can only be used
to receive notifications about a plugged in/out device.

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Link: https://lore.kernel.org/r/20210302164709.3142702-8-anton.yakovlev@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-03-07 09:08:11 +01:00
Anton Yakovlev
da76e9f3e4 ALSA: virtio: PCM substream operators
Introduce the operators required for the operation of substreams.

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Link: https://lore.kernel.org/r/20210302164709.3142702-7-anton.yakovlev@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-03-07 09:08:03 +01:00
Anton Yakovlev
f40a28679e ALSA: virtio: handling control and I/O messages for the PCM device
The driver implements a message-based transport for I/O substream
operations. Before the start of the substream, the hardware buffer is
sliced into I/O messages, the number of which is equal to the current
number of periods. The size of each message is equal to the current
size of one period.

I/O messages are organized in an ordered queue. The completion of the
I/O message indicates an elapsed period (the only exception is the end
of the stream for the capture substream). Upon completion, the message
is automatically re-added to the end of the queue.

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Link: https://lore.kernel.org/r/20210302164709.3142702-6-anton.yakovlev@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-03-07 09:07:44 +01:00
Anton Yakovlev
29b96bf50b ALSA: virtio: build PCM devices and substream hardware descriptors
Like the HDA specification, the virtio sound device specification links
PCM substreams, jacks and PCM channel maps into functional groups. For
each discovered group, a PCM device is created, the number of which
coincides with the group number.

Introduce the module parameters for setting the hardware buffer
parameters:
  pcm_buffer_ms [=160]
  pcm_periods_min [=2]
  pcm_periods_max [=16]
  pcm_period_ms_min [=10]
  pcm_period_ms_max [=80]

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Link: https://lore.kernel.org/r/20210302164709.3142702-5-anton.yakovlev@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-03-07 09:07:35 +01:00
Anton Yakovlev
9d45e514da ALSA: virtio: handling control messages
The control queue can be used by different parts of the driver to send
commands to the device. Control messages can be either synchronous or
asynchronous. The lifetime of a message is controlled by a reference
count.

Introduce a module parameter to set the message completion timeout:
  msg_timeout_ms [=1000]

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Link: https://lore.kernel.org/r/20210302164709.3142702-4-anton.yakovlev@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-03-07 09:07:27 +01:00
Anton Yakovlev
de3a9980d8 ALSA: virtio: add virtio sound driver
Introduce skeleton of the virtio sound driver. The driver implements
the virtio sound device specification, which has become part of the
virtio standard.

Initial initialization of the device, virtqueues and creation of an
empty ALSA sound device.

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Link: https://lore.kernel.org/r/20210302164709.3142702-3-anton.yakovlev@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2021-03-07 09:07:16 +01:00