3.19.8-ckt12 -stable review patch. If anyone has any objections, please let me know.
------------------ From: Clemens Ladisch <clem...@ladisch.de> commit 1ca8b201309d842642f221db7f02f71c0af5be2d upstream. The CH345 USB MIDI chip has two output ports. However, they are multiplexed through one pin, and the number of ports cannot be reduced even for hardware that implements only one connector, so for those devices, data sent to either port ends up on the same hardware output. This becomes a problem when both ports are used at the same time, as longer MIDI commands (such as SysEx messages) are likely to be interrupted by messages from the other port, and thus to get lost. It would not be possible for the driver to detect how many ports the device actually has, except that in practice, _all_ devices built with the CH345 have only one port. So we can just ignore the device's descriptors, and hardcode one output port. Signed-off-by: Clemens Ladisch <clem...@ladisch.de> Signed-off-by: Takashi Iwai <ti...@suse.de> Signed-off-by: Kamal Mostafa <ka...@canonical.com> --- sound/usb/midi.c | 3 +++ sound/usb/quirks-table.h | 11 +++++++++++ sound/usb/quirks.c | 1 + sound/usb/usbaudio.h | 1 + 4 files changed, 16 insertions(+) diff --git a/sound/usb/midi.c b/sound/usb/midi.c index f5bcacc..d968cc3 100644 --- a/sound/usb/midi.c +++ b/sound/usb/midi.c @@ -2377,6 +2377,9 @@ int snd_usbmidi_create(struct snd_card *card, err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints); break; + case QUIRK_MIDI_CH345: + err = snd_usbmidi_detect_per_port_endpoints(umidi, endpoints); + break; default: dev_err(&umidi->dev->dev, "invalid quirk type %d\n", quirk->type); diff --git a/sound/usb/quirks-table.h b/sound/usb/quirks-table.h index b531993..f968c67 100644 --- a/sound/usb/quirks-table.h +++ b/sound/usb/quirks-table.h @@ -2824,6 +2824,17 @@ YAMAHA_DEVICE(0x7010, "UB99"), .idProduct = 0x1020, }, +/* QinHeng devices */ +{ + USB_DEVICE(0x1a86, 0x752d), + .driver_info = (unsigned long) &(const struct snd_usb_audio_quirk) { + .vendor_name = "QinHeng", + .product_name = "CH345", + .ifnum = 1, + .type = QUIRK_MIDI_CH345 + } +}, + /* KeithMcMillen Stringport */ { USB_DEVICE(0x1f38, 0x0001), diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c index 449555c..9032510b 100644 --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -535,6 +535,7 @@ int snd_usb_create_quirk(struct snd_usb_audio *chip, [QUIRK_MIDI_CME] = create_any_midi_quirk, [QUIRK_MIDI_AKAI] = create_any_midi_quirk, [QUIRK_MIDI_FTDI] = create_any_midi_quirk, + [QUIRK_MIDI_CH345] = create_any_midi_quirk, [QUIRK_AUDIO_STANDARD_INTERFACE] = create_standard_audio_quirk, [QUIRK_AUDIO_FIXED_ENDPOINT] = create_fixed_stream_quirk, [QUIRK_AUDIO_EDIROL_UAXX] = create_uaxx_quirk, diff --git a/sound/usb/usbaudio.h b/sound/usb/usbaudio.h index 91d0380..991aa84 100644 --- a/sound/usb/usbaudio.h +++ b/sound/usb/usbaudio.h @@ -94,6 +94,7 @@ enum quirk_type { QUIRK_MIDI_AKAI, QUIRK_MIDI_US122L, QUIRK_MIDI_FTDI, + QUIRK_MIDI_CH345, QUIRK_AUDIO_STANDARD_INTERFACE, QUIRK_AUDIO_FIXED_ENDPOINT, QUIRK_AUDIO_EDIROL_UAXX, -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/