Re: [PATCH] Add support for Mobilcom Debitel USB UMTS Surf-Stickto option driver

From: Gernot Hillier
Date: Tue Nov 24 2009 - 13:01:10 EST


Hi!

Oliver Neukum schrieb:
Am Sonntag, 22. November 2009 09:08:44 schrieb Gernot Hillier:
In addition, this device seems to ignore setting of RTS/DTR by option_send_
setup and doesn't answer the usb_control_msg leading to a 5 s timeout
(USB_CTRL_SET_TIMEOUT) in userspace open() and other operations. As this
confused several impatient userspace applications like Minicom and
ModemManager, I decided to reduce the timeout to more reasonable 1000 ms.
I don't think the usual USB GSM stick needs longer, so this should be
safe.

Unfortunately the 5s timeout comes from the USB spec for control
messages. So reducing it is a serious matter. In this case I'd prefer
if you introduce a special case for these devices and fail the operation
without doing any IO.

Thanks for the answer and suggestion. I looked into that - but unfortunately (again), it isn't that easy. The device accepts the option_set_setup triggered control message on *one* of its three interfaces while it silently ignores it on the other two. :-(

I do see /dev/ttyUSB[0-2] - and on /dev/ttyUSB2, everything works as expected (i.e. the control message *is* handled correctly) while ttyUSB0 and ttyUSB1 exhibit this strange timeout issue.

As you might have expected, I have no detailed spec about the device which could explain this. I can only say that the device reacts on AT commands on ttyUSB1 and ttyUSB2 while ttyUSB0 seems to serve other purposes.

What do you think - shall I disable sending the usb control message depending on bInterfaceNumber? Any better ideas?

Here's the "lsusb -v" output in case this helps:

Bus 002 Device 007: ID 1c9e:9603
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x1c9e
idProduct 0x9603
bcdDevice 0.00
iManufacturer 2 USB Modem
iProduct 1 Modem Configuration
iSerial 3 1234567890ABCDEF
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 108
bNumInterfaces 4
bConfigurationValue 1
iConfiguration 1 Modem Configuration
bmAttributes 0xe0
Self Powered
Remote Wakeup
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 255 Vendor Specific Subclass
bInterfaceProtocol 255 Vendor Specific Protocol
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 32
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 32
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 255 Vendor Specific Subclass
bInterfaceProtocol 255 Vendor Specific Protocol
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 32
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 32
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 3
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 255 Vendor Specific Subclass
bInterfaceProtocol 255 Vendor Specific Protocol
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 0x0040 1x 64 bytes
bInterval 5
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x84 EP 4 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 32
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x03 EP 3 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 32
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 3
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 8 Mass Storage
bInterfaceSubClass 6 SCSI
bInterfaceProtocol 80 Bulk (Zip)
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x04 EP 4 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x85 EP 5 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Device Qualifier (for other device speed):
bLength 10
bDescriptorType 6
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
bNumConfigurations 1
Device Status: 0x0000
(Bus Powered)

--
Gernot
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