From ac77423609aa499265a0ab75c497661bc7157f37 Mon Sep 17 00:00:00 2001 From: "Keith A. Milner" Date: Sun, 11 Oct 2015 15:19:48 +0100 Subject: [PATCH] ALSA: usb-audio: Allow any MIDI endpoint to drive use of interrupt transfer on newer Roland devices This patch enables interrupt transfer mode for MIDI ports on newer Boss/Roland devices such as the GT-100/001 which support interrupt transfer on both IN and OUT MIDI endpoints. Previously this wasn't being enabled for these devices as the code was specifically looking for the scenario where the IN endpoint supported interrupt transfer and the OUT endpoint was bulk transfer. Newer devices support interrupt transfer for both endpoints. This has been tested on Boss devices GT-001, BR-80 and JS-8 and Roland VS-20. It would benefit from some regresison testing with other devices if possible. Signed-off-by: Keith A. Milner Signed-off-by: Takashi Iwai --- sound/usb/midi.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/sound/usb/midi.c b/sound/usb/midi.c index 417ebb11cf48..7661616f3636 100644 --- a/sound/usb/midi.c +++ b/sound/usb/midi.c @@ -1903,11 +1903,14 @@ static void snd_usbmidi_switch_roland_altsetting(struct snd_usb_midi *umidi) hostif = &intf->altsetting[1]; intfd = get_iface_desc(hostif); + /* If either or both of the endpoints support interrupt transfer, + * then use the alternate setting + */ if (intfd->bNumEndpoints != 2 || - (get_endpoint(hostif, 0)->bmAttributes & - USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_BULK || - (get_endpoint(hostif, 1)->bmAttributes & - USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_INT) + !((get_endpoint(hostif, 0)->bmAttributes & + USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT || + (get_endpoint(hostif, 1)->bmAttributes & + USB_ENDPOINT_XFERTYPE_MASK) == USB_ENDPOINT_XFER_INT)) return; dev_dbg(&umidi->dev->dev, "switching to altsetting %d with int ep\n",