diff options
| author | Clemens Ladisch <clemens@ladisch.de> | 2013-02-03 22:31:20 +0100 |
|---|---|---|
| committer | Clemens Ladisch <clemens@ladisch.de> | 2013-06-27 21:59:47 +0200 |
| commit | ba7c2be114243fa4cfcbc66a81db18e1d55abf4b (patch) | |
| tree | 0452886296dc4564d4ca7cd5105231d74e97d88a /sound | |
| parent | 8f898e92aea2c24c7f379ee265d178f69ebb9c07 (diff) | |
ALSA: usb-audio: detect implicit feedback on Roland devices
All the Roland/Edirol/BOSS USB audio devices that need implicit feedback
show this unambiguously in their descriptors, so it might be a good idea
to let the driver detect this.
This should make playback work correctly (at least with Jack) with the
following devices:
- BOSS GT-100
- BOSS JS-8 Jam Station
- Edirol M-16DX
- Roland GAIA SH-01
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/usb/pcm.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index 776c58c7cba..15b151ed489 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -298,6 +298,35 @@ static int deactivate_endpoints(struct snd_usb_substream *subs) return 0; } +static int search_roland_implicit_fb(struct usb_device *dev, int ifnum, + unsigned int altsetting, + struct usb_host_interface **alts, + unsigned int *ep) +{ + struct usb_interface *iface; + struct usb_interface_descriptor *altsd; + struct usb_endpoint_descriptor *epd; + + iface = usb_ifnum_to_if(dev, ifnum); + if (!iface || iface->num_altsetting < altsetting + 1) + return -ENOENT; + *alts = &iface->altsetting[altsetting]; + altsd = get_iface_desc(*alts); + if (altsd->bAlternateSetting != altsetting || + altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC || + (altsd->bInterfaceSubClass != 2 && + altsd->bInterfaceProtocol != 2 ) || + altsd->bNumEndpoints < 1) + return -ENOENT; + epd = get_endpoint(*alts, 0); + if (!usb_endpoint_is_isoc_in(epd) || + (epd->bmAttributes & USB_ENDPOINT_USAGE_MASK) != + USB_ENDPOINT_USAGE_IMPLICIT_FB) + return -ENOENT; + *ep = epd->bEndpointAddress; + return 0; +} + /* * find a matching format and set up the interface */ @@ -393,6 +422,18 @@ static int set_format(struct snd_usb_substream *subs, struct audioformat *fmt) goto add_sync_ep; } } + if (is_playback && + attr == USB_ENDPOINT_SYNC_ASYNC && + altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC && + altsd->bInterfaceProtocol == 2 && + altsd->bNumEndpoints == 1 && + USB_ID_VENDOR(subs->stream->chip->usb_id) == 0x0582 /* Roland */ && + search_roland_implicit_fb(dev, altsd->bInterfaceNumber + 1, + altsd->bAlternateSetting, + &alts, &ep) >= 0) { + implicit_fb = 1; + goto add_sync_ep; + } if (((is_playback && attr == USB_ENDPOINT_SYNC_ASYNC) || (!is_playback && attr == USB_ENDPOINT_SYNC_ADAPTIVE)) && |