Re: ConfigFS: bcdUSB forced to 0x0210

[Felipe Balbi <balbi@kernel.org>]

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Hi,

"Sid Spry" <sid@aeam.us> writes:
>> >> "Sid Spry" <sid@aeam.us> writes:
>> >> > Hi, I can't enable USB3 with e.g. f_ncm because bcdUSB is always reset to 0x0210:
>> >> >
>> >> > $ sudo sh -c 'echo "0x0300" > /sys/kernel/config/usb_gadget/g11/bcdUSB'
>> >> > $ cat /sys/kernel/config/usb_gadget/g11/bcdUSB 
>> >> > 0x0300
>> >> > $ sudo sh -c 'echo "fe800000.usb" > /sys/kernel/config/usb_gadget/g11/UDC'
>> >> > $ cat /sys/kernel/config/usb_gadget/g11/bcdUSB 
>> >> > 0x0210
>> >> > $ tree /sys/kernel/config/usb_gadget/g11
>> >> > /sys/kernel/config/usb_gadget/g11
>> >> > ├── bcdDevice
>> >> > ├── bcdUSB
>> >> > ├── bDeviceClass
>> >> > ├── bDeviceProtocol
>> >> > ├── bDeviceSubClass
>> >> > ├── bMaxPacketSize0
>> >> > ├── configs
>> >> > │   └── c.1
>> >> > │       ├── bmAttributes
>> >> > │       ├── MaxPower
>> >> > │       ├── ncm.0 -> ../../../../usb_gadget/g11/functions/ncm.0
>> >> > │       └── strings
>> >> > │           └── 0x409
>> >> > │               └── configuration
>> >> > ├── functions
>> >> > │   └── ncm.0
>> >> > │       ├── dev_addr
>> >> > │       ├── host_addr
>> >> > │       ├── ifname
>> >> > │       ├── os_desc
>> >> > │       │   └── interface.ncm
>> >> > │       │       ├── compatible_id
>> >> > │       │       └── sub_compatible_id
>> >> > │       └── qmult
>> >> > ├── idProduct
>> >> > ├── idVendor
>> >> > ├── max_speed
>> >> > ├── os_desc
>> >> > │   ├── b_vendor_code
>> >> > │   ├── qw_sign
>> >> > │   └── use
>> >> > ├── strings
>> >> > │   └── 0x409
>> >> > │       ├── manufacturer
>> >> > │       ├── product
>> >> > │       └── serialnumber
>> >> > └── UDC
>> >> >
>> >> > Board is a RK3399 based RockPro64.
>> >> 
>> >> what's your max_speed?
>> >> 
>> >
>> > $ cat /sys/kernel/config/usb_gadget/g11/max_speed 
>> > super-speed
>> >
>> > Looks ok. From Windows, the xHCI driver reports that the device supports
>> > super speed but chooses high speed. I can't see this info from a Linux host.
>> 
>> It's probably failing Rx.Detect and falling back to high-speed. Which
>> USB Peripheral Controller is that?
>> 
>
> It's a dwc3. I recently found that if I plug the device into itself (there are two
> dwc3, one on a C port, one on a female A port) the device enumerates at
> superspeed with the NCM configfs driver. But connecting to my x86 machines
> fails.
>
> In an earlier thread I found that the type C port would not work with USB2
> or 3 if in the "normal" direction (as opposed to "reversed").

sounds like a board layout problem to me. Can you capture dwc3
tracepoints? More information here:
https://www.kernel.org/doc/html/latest/driver-api/usb/dwc3.html#reporting-bugs

-- 
balbi

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