From 362ff1e7c6c20f8d6ebe20682870d471373c608b Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Thu, 13 Feb 2025 17:18:25 +0100 Subject: [PATCH] virtio_snd.h: clarify that `controls` depends on VIRTIO_SND_F_CTLS MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit As defined in the specification, the `controls` field in the configuration space is only valid/present if VIRTIO_SND_F_CTLS is negotiated. From https://docs.oasis-open.org/virtio/virtio/v1.3/virtio-v1.3.html: 5.14.4 Device Configuration Layout ... controls (driver-read-only) indicates a total number of all available control elements if VIRTIO_SND_F_CTLS has been negotiated. Let's use the same style used in virtio_blk.h to clarify this and to avoid confusion as happened in QEMU (see link). Link: https://gitlab.com/qemu-project/qemu/-/issues/2805 Signed-off-by: Stefano Garzarella Acked-by: Eugenio Pérez Signed-off-by: Takashi Iwai Link: https://patch.msgid.link/20250213161825.139952-1-sgarzare@redhat.com --- include/uapi/linux/virtio_snd.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/uapi/linux/virtio_snd.h b/include/uapi/linux/virtio_snd.h index 5f4100c2cf04..a4cfb9f6561a 100644 --- a/include/uapi/linux/virtio_snd.h +++ b/include/uapi/linux/virtio_snd.h @@ -25,7 +25,7 @@ struct virtio_snd_config { __le32 streams; /* # of available channel maps */ __le32 chmaps; - /* # of available control elements */ + /* # of available control elements (if VIRTIO_SND_F_CTLS) */ __le32 controls; };