From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from ws5-mx01.kavi.com (ws5-mx01.kavi.com [34.193.7.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BCB39C4332F for ; Thu, 9 Nov 2023 16:46:50 +0000 (UTC) Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by ws5-mx01.kavi.com (Postfix) with ESMTP id EA3922237D for ; Thu, 9 Nov 2023 16:46:49 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id B92EC986CE7 for ; Thu, 9 Nov 2023 16:46:49 +0000 (UTC) Received: from host09.ws5.connectedcommunity.org (host09.ws5.connectedcommunity.org [10.110.1.97]) by lists.oasis-open.org (Postfix) with QMQP id 8ABB6986CDB; Thu, 9 Nov 2023 16:46:49 +0000 (UTC) Mailing-List: contact virtio-dev-help@lists.oasis-open.org; run by ezmlm List-ID: Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 30E58986CDC for ; Thu, 9 Nov 2023 16:46:49 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com From: Radu Ocica To: Matias Ezequiel Vara Larsen CC: "virtio-dev@lists.oasis-open.org" , "anton.yakovlev@opensynergy.com" Thread-Topic: [virtio-dev] virtio-snd comments/questions Thread-Index: AQHaAdgPGZsaTwL9FEiOAsMZLVwCl7BZBi2AgA/8OmuABNQTgIAEeavR Date: Thu, 9 Nov 2023 16:46:45 +0000 Message-ID: <37eaf0dc2bdb4a7b936618b48dd00ac2@blackberry.com> References: <02725a6508584ed2aa8b31c9e9f4264a@blackberry.com> <6df30c7945ca4ac2bb1c170b1c028719@blackberry.com>, In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [100.64.197.67] Content-Type: multipart/alternative; boundary="_000_37eaf0dc2bdb4a7b936618b48dd00ac2blackberrycom_" MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.987,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-11-09_14,2023-11-09_01,2023-05-22_02 Subject: Re: [virtio-dev] virtio-snd comments/questions --_000_37eaf0dc2bdb4a7b936618b48dd00ac2blackberrycom_ Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1" > Could you elaborate on this? Which audio backend would not support > PAUSE? I am not very familiar with audio engines. For instance in linux, alsa-lib has a flag that specifies pause support by = a PCM stream: #define SNDRV_PCM_INFO_PAUSE (1UL<<19) /* pause ioct= l is supported */ The snd_pcm_pause API can only be used successfully if the PCM stream has t= his bit set in its PCM info. A similar concept exists in QNX sound. >> This looks promising. I found it already at https://urldefense.com/v3/__= https://github.com/torvalds/linux/blob/master/sound/virtio/__;!!JoeW-IhCUkS= 0Jg!bBq1USPrJoN1_CBJkW-XBknkCSEOUP40V1ctr_OU0tsYyEr9pXjSEu7n5ibc5BL4fKT3Utk= -cpGw6FiWxDY$ and will give it a try. Is there a repository for this drive= r code where both this fix and the audio control support is available? >> >> > What do you mean with audio control support? Are you talking about the > device? The device implementation is at https://urldefense.com/v3/__https://github.com/rust-vmm/vhost-device/tree/m= ain/staging__;!!JoeW-IhCUkS0Jg!bBq1USPrJoN1_CBJkW-XBknkCSEOUP40V1ctr_OU0tsY= yEr9pXjSEu7n5ibc5BL4fKT3Utk-cpGw1sNq6IY$ . I meant the support for feature VIRTIO_SND_F_CTLS in the virtio_snd guest d= river. A patch to add this support is available here: https://lists.oasis-o= pen.org/archives/virtio-comment/202104/msg00013.html. However this patch is= not present in the virtio_snd guest driver version here: https://urldefens= e.com/v3/__https://github.com/torvalds/linux/blob/master/sound/virtio/__;!!= JoeW-IhCUkS0Jg!bBq1USPrJoN1_CBJkW-XBknkCSEOUP40V1ctr_OU0tsYyEr9pXjSEu7n5ibc= 5BL4fKT3Utk-cpGw6FiWxDY$ . I was wondering whether there is a repository wh= ere the virtio_snd driver has both the VIRTIO_SND_F_CTLS support and the ac= k callback patch. ---------------------------------------------------------------------- This transmission (including any attachments) may contain confidential info= rmation, privileged material (including material protected by the solicitor= -client or other applicable privileges), or constitute non-public informati= on. Any use of this information by anyone other than the intended recipient= is prohibited. If you have received this transmission in error, please imm= ediately reply to the sender and delete this information from your system. = Use, dissemination, distribution, or reproduction of this transmission by u= nintended recipients is not authorized and may be unlawful. --_000_37eaf0dc2bdb4a7b936618b48dd00ac2blackberrycom_ Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="iso-8859-1"


> Could you elaborate on this? Which audio backend would not support
> PAUSE? I am not very familiar with audio engines.

For instance in linux, alsa-lib has a flag that sp= ecifies pause support by a PCM stream:
#define SNDRV_PCM_INFO_PAUSE  &nbs= p;            &= nbsp;       (1UL<<19)  /* pause io= ctl is supported */
The snd_pcm_pause API can only be used successfull= y if the PCM stream has this bit set in its PCM info.
A similar concept exists in QNX sound. 



>> This looks promis= ing. I found it already at https://urldefense.com/v3/__https://github.com/torvalds/linux/blob/master/s= ound/virtio/__;!!JoeW-IhCUkS0Jg!bBq1USPrJoN1_CBJkW-XBknkCSEOUP40V1ctr_OU0ts= YyEr9pXjSEu7n5ibc5BL4fKT3Utk-cpGw6FiWxDY$  and will give it a try.= Is there a repository for this driver code where both this fix and the audio control support is available?
>>
>>

> What do you mean with audio control support? Are you talking about the=
> device? The device implementation is at
https://urldefense.com= /v3/__https://github.com/rust-vmm/vhost-device/tree/main/staging__;!!JoeW-I= hCUkS0Jg!bBq1USPrJoN1_CBJkW-XBknkCSEOUP40V1ctr_OU0tsYyEr9pXjSEu7n5ibc5BL4fK= T3Utk-cpGw1sNq6IY$ .

I meant the support for feature VIRTIO_SND_F_CTLS in the virtio_snd g= uest driver. A patch to add this support is available here: https://lists.oasis-open.org/archives/virtio-comment/202104/msg00013.html. However this patch is not present in the virtio_snd guest driver versio= n here: https://urldefense.com/v3/__https://github.com/torvalds/linux/blob/master/s= ound/virtio/__;!!JoeW-IhCUkS0Jg!bBq1USPrJoN1_CBJkW-XBknkCSEOUP40V1ctr_OU0ts= YyEr9pXjSEu7n5ibc5BL4fKT3Utk-cpGw6FiWxDY$ . I was wondering whether the= re is a repository where the virtio_snd driver has both the VIRTIO_SND_F_CTLS support and the ack cal= lback patch.

This transmission (including any attachments) may contain confidential = information, privileged material (including material protected by the solic= itor-client or other applicable privileges), or constitute non-public infor= mation. Any use of this information by anyone other than the intended recip= ient is prohibited. If you have received this transmission in error, please= immediately reply to the sender and delete this information from your syst= em. Use, dissemination, distribution, or reproduction of this transmission = by unintended recipients is not authorized and may be unlawful.
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