This is a note to let you know that I've just added the patch titled usb: cdc_acm: Add quirk for Elatec TWN3 to my usb git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git in the usb-linus branch. The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.) The patch will hopefully also be merged in Linus's tree for the next -rc kernel release. If you have any questions about this process, please let me know. >From 765fb2f181cad669f2beb87842a05d8071f2be85 Mon Sep 17 00:00:00 2001 From: Maksim Salau <msalau@xxxxxxxxxxx> Date: Wed, 11 Oct 2017 11:10:52 +0300 Subject: usb: cdc_acm: Add quirk for Elatec TWN3 Elatec TWN3 has the union descriptor on data interface. This results in failure to bind the device to the driver with the following log: usb 1-1.2: new full speed USB device using streamplug-ehci and address 4 usb 1-1.2: New USB device found, idVendor=09d8, idProduct=0320 usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=0 usb 1-1.2: Product: RFID Device (COM) usb 1-1.2: Manufacturer: OEM cdc_acm 1-1.2:1.0: Zero length descriptor references cdc_acm: probe of 1-1.2:1.0 failed with error -22 Adding the NO_UNION_NORMAL quirk for the device fixes the issue. `lsusb -v` of the device: Bus 001 Device 003: ID 09d8:0320 Device Descriptor: bLength 18 bDescriptorType 1 bcdUSB 2.00 bDeviceClass 2 Communications bDeviceSubClass 0 bDeviceProtocol 0 bMaxPacketSize0 32 idVendor 0x09d8 idProduct 0x0320 bcdDevice 3.00 iManufacturer 1 OEM iProduct 2 RFID Device (COM) iSerial 0 bNumConfigurations 1 Configuration Descriptor: bLength 9 bDescriptorType 2 wTotalLength 67 bNumInterfaces 2 bConfigurationValue 1 iConfiguration 0 bmAttributes 0x80 (Bus Powered) MaxPower 250mA Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 0 bAlternateSetting 0 bNumEndpoints 1 bInterfaceClass 2 Communications bInterfaceSubClass 2 Abstract (modem) bInterfaceProtocol 1 AT-commands (v.25ter) iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x83 EP 3 IN bmAttributes 3 Transfer Type Interrupt Synch Type None Usage Type Data wMaxPacketSize 0x0020 1x 32 bytes bInterval 2 Interface Descriptor: bLength 9 bDescriptorType 4 bInterfaceNumber 1 bAlternateSetting 0 bNumEndpoints 2 bInterfaceClass 10 CDC Data bInterfaceSubClass 0 Unused bInterfaceProtocol 0 iInterface 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x02 EP 2 OUT bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0020 1x 32 bytes bInterval 0 Endpoint Descriptor: bLength 7 bDescriptorType 5 bEndpointAddress 0x81 EP 1 IN bmAttributes 2 Transfer Type Bulk Synch Type None Usage Type Data wMaxPacketSize 0x0020 1x 32 bytes bInterval 0 CDC Header: bcdCDC 1.10 CDC Call Management: bmCapabilities 0x03 call management use DataInterface bDataInterface 1 CDC ACM: bmCapabilities 0x06 sends break line coding and serial state CDC Union: bMasterInterface 0 bSlaveInterface 1 Device Status: 0x0000 (Bus Powered) Signed-off-by: Maksim Salau <msalau@xxxxxxxxxxx> Acked-by: Oliver Neukum <oneukum@xxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/class/cdc-acm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 5e056064259c..18c923a4c16e 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1832,6 +1832,9 @@ static const struct usb_device_id acm_ids[] = { { USB_DEVICE(0xfff0, 0x0100), /* DATECS FP-2000 */ .driver_info = NO_UNION_NORMAL, /* reports zero length descriptor */ }, + { USB_DEVICE(0x09d8, 0x0320), /* Elatec GmbH TWN3 */ + .driver_info = NO_UNION_NORMAL, /* has misplaced union descriptor */ + }, { USB_DEVICE(0x2912, 0x0001), /* ATOL FPrint */ .driver_info = CLEAR_HALT_CONDITIONS, -- 2.14.2