From 8e0cd23f7163f7f203bdaffd9f06feaa49dcec2d Mon Sep 17 00:00:00 2001 From: Joonas Kankaala Date: Sat, 9 Mar 2024 19:29:32 +0200 Subject: [PATCH] usb-audio: Fix invalid values in AudioControl descriptors MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This fixes the invalid bInterfaceProtocol value 0x04 in the USB audio AudioControl descriptors. It should be zero. While Linux and Windows forgive this error, macOS 14 Sonoma does not. The usb-audio device does not appear in macOS sound settings even though the device is recognized and shows up in USB system information. According to the USB audio class specs 1.0-4.0, valid values are 0x00, 0x20, 0x30 and 0x40. (Note also that Linux prints the warning "unknown interface protocol 0x4, assuming v1", but then proceeds as if the value was zero.) This also fixes the invalid wTotalLength value in the multi-channel setup AudioControl interface header descriptor (used when multi=on and out.mixing-engine off). The combined length of all the descriptors there add up to 0x37, not 0x38. In Linux, "lsusb -D ..." displays incomplete descriptor information when this length is incorrect. Signed-off-by: Joonas Kankaala Reviewed-by: Volker Rümelin Reviewed-by: Michael Tokarev Signed-off-by: Michael Tokarev --- hw/usb/dev-audio.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/hw/usb/dev-audio.c b/hw/usb/dev-audio.c index d5ac1f8962..1897fff9e6 100644 --- a/hw/usb/dev-audio.c +++ b/hw/usb/dev-audio.c @@ -124,7 +124,6 @@ static const USBDescIface desc_iface[] = { .bNumEndpoints = 0, .bInterfaceClass = USB_CLASS_AUDIO, .bInterfaceSubClass = USB_SUBCLASS_AUDIO_CONTROL, - .bInterfaceProtocol = 0x04, .iInterface = STRING_USBAUDIO_CONTROL, .ndesc = 4, .descs = (USBDescOther[]) { @@ -282,7 +281,6 @@ static const USBDescIface desc_iface_multi[] = { .bNumEndpoints = 0, .bInterfaceClass = USB_CLASS_AUDIO, .bInterfaceSubClass = USB_SUBCLASS_AUDIO_CONTROL, - .bInterfaceProtocol = 0x04, .iInterface = STRING_USBAUDIO_CONTROL, .ndesc = 4, .descs = (USBDescOther[]) { @@ -293,7 +291,7 @@ static const USBDescIface desc_iface_multi[] = { USB_DT_CS_INTERFACE, /* u8 bDescriptorType */ DST_AC_HEADER, /* u8 bDescriptorSubtype */ U16(0x0100), /* u16 bcdADC */ - U16(0x38), /* u16 wTotalLength */ + U16(0x37), /* u16 wTotalLength */ 0x01, /* u8 bInCollection */ 0x01, /* u8 baInterfaceNr */ }