---------- Forwarded message ---------
>From: Johan Hovold <johan@***************>
>Date: Thu, Jan 31, 2019 at 9:27 AM
>Subject: Re: MT65xx Preloader 0e8d:2000, Kernel 4.20.5.1
>To: Carlos Salvador Pérez Salgado <ing.salvadorperez@***************>
>Cc: Johan Hovold <jhovold@***************>
>On Thu, Jan 31, 2019 at 05:57:01AM -0600, Carlos Salvador Pérez Salgado wrote:
>> Hello,
>>
>> first of all, I want to apologize for the annoyance this message could
>> cause to you.
>> The matter is that I want to flash a pair of cell phones which are
>> softbricked and I don't use MS Windows at any of my computers.
><
>> I am currently using Artix linux with kernel 4.20.5.1. When I plug any of
>> the phones with their battery removed, the Kernel identifies the device as
>> MT65xxx Preloader and cdc_acm kicks in; the problem is that probing the
>> device fails with error -22, and the reason given is "Zero length
>> descriptor references", which as far I could understand in the source file
>> of cdc_acm, is the response given when the driver fails.
>>
>> Should I need any firmware to get it work? Am I doing something wrong?
>>
>> Salvador Pérez
>
>You can try setting the NO_UNION_NORMAL flag for your device (e.g. in
>the driver).
>Make sure to include the output of "lsusb -v" for your device in your
>report. And make sure to include any privacy footers in your mail when
>posting to the list.
>
>Johan
Here I add the requested information.
I had to use a loop in order to pipe this to a file because the device
disappears very fast.
$ lsusb -v -d 0e8d:2000
Bus 001 Device 002: ID 0e8d:2000 MediaTek Inc. MT65xx Preloader
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 2 Communications
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 64
idVendor 0x0e8d MediaTek Inc.
idProduct 0x2000 MT65xx Preloader
bcdDevice 1.00
iManufacturer 1 MediaTek
iProduct 2 MT65xx Preloader
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x0046
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 3 USB CDC ACM for preloader
bmAttributes 0xc0
Self Powered
MaxPower 500mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 10 CDC Data
bInterfaceSubClass 0
bInterfaceProtocol 0
iInterface 4 CDC ACM Data Interface
Endpoint Descriptor:
bLength 8
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Endpoint Descriptor:
bLength 8
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0200 1x 512 bytes
bInterval 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 2 Communications
bInterfaceSubClass 2 Abstract (modem)
bInterfaceProtocol 1 AT-commands (v.25ter)
iInterface 5 CDC ACM Communication Interface
CDC Header:
bcdCDC 1.10
CDC ACM:
bmCapabilities 0x0f
connection notifications
sends break
line coding and serial state
get/set/clear comm features
CDC Union:
bMasterInterface 1
bSlaveInterface 0
CDC Call Management:
bmCapabilities 0x03
call management
use DataInterface
bDataInterface 0
Endpoint Descriptor:
bLength 8
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 16
can't get debug descriptor: Resource temporarily unavailable
Device Status: 0x0001
Self Powered
I had also found this thread which seems related:
https://www.spinics.net/lists/linux-usb/msg175130.html
Salvador
