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| author | Sebastian Dalfuß <sd@sedf.de> | 2026-09-05 14:11:12 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2026-09-06 10:12:35 +0200 |
| commit | 45b5beb60bf7bd41c55ef17f6f2d28b351fad6c0 (patch) | |
| tree | 9956a0471a4e52c160086617190ac8716fa5b22d | |
| parent | 12cba0ce111c2caabf4ff24dc5538959813664c0 (diff) | |
| download | linux-next-45b5beb60bf7bd41c55ef17f6f2d28b351fad6c0.tar.gz linux-next-45b5beb60bf7bd41c55ef17f6f2d28b351fad6c0.zip | |
ALSA: usb-audio: Add boot quirk for Behringer CM1A
After a power cycle and reenumeration, the Behringer CM1A* leaves its
MIDI endpoint inoperative. USB enumeration and driver binding
complete successfully, but MIDI outputs remain pending.
A GET_DESCRIPTOR request for the device descriptor, issued after USB
configuration, makes the endpoint operational. Add a one time boot quirk
to perform that request before ALSA initializes the device.
*
ID 1397:1234 BEHRINGER International GmbH CM1A
Signed-off-by: Sebastian Dalfuß <sd@sedf.de>
Link: https://patch.msgid.link/apwG4DRfNyvmRzyb@sedf.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
| -rw-r--r-- | sound/usb/quirks.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c index 91938172912a..5dede66ea69e 100644 --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -850,6 +850,27 @@ static int snd_usb_accessmusic_boot_quirk(struct usb_device *dev) } /* + * A post configuration device descriptor read is needed to make the CM1A + * operational after reenumeration. + */ +static int snd_usb_cm1a_boot_quirk(struct usb_device *dev) +{ + struct usb_device_descriptor *desc __free(kfree) = kmalloc_obj(*desc); + int err; + + if (!desc) + return -ENOMEM; + + err = usb_get_descriptor(dev, USB_DT_DEVICE, 0, desc, sizeof(*desc)); + if (err < 0) { + dev_err(&dev->dev, "failed to read device descriptor: %d\n", err); + return err; + } + + return 0; +} + +/* * Some sound cards from Native Instruments are in fact compliant to the USB * audio standard of version 2 and other approved USB standards, even though * they come up as vendor-specific device when first connected. @@ -1681,6 +1702,8 @@ int snd_usb_apply_boot_quirk_once(struct usb_device *dev, switch (id) { case USB_ID(0x07fd, 0x0008): /* MOTU M Series, 1st hardware version */ return snd_usb_motu_m_series_boot_quirk(dev); + case USB_ID(0x1397, 0x1234): /* Behringer CM1A */ + return snd_usb_cm1a_boot_quirk(dev); } return 0; |