Re: [PATCH v2 2/4] usb: common: Move u_serial from gadget/function to usb/common

[Lu Baolu]

Hi,

On 08/08/2017 02:14 PM, Felipe Balbi wrote:
> Hi,
>
> Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> writes:
>>> Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx> writes:
>>>> The component u_serial provides a glue layer between TTY layer
>>>> and a USB gadget device needed to provide a basic serial port
>>>> functionality. Currently, u_serial sits under gadget/function
>>>> and depends on CONFIG_USB_GADGET to be compiled and used.
>>>>
>>>> Most of the serial gadget devices are based on a UDC (USB device
>>>> controller) and implemented by making use of the Linux gadget
>>>> frameworks. But we are facing other implementions as well. One
>>>> example can be found with xHCI debug capability. The xHCI debug
>>>> capability implements a serial gadget with hardware and firmware,
>>>> and provides an interface similar with xHCI host for submitting
>>>> and reaping the transfer requests.
>>>>
>>>> In order to make better use of u_serial when implementing xHCI
>>>> debug capability in xHCI driver, this patch moves u_serial.c
>>>> from gadget/function to usb/common, and moves u_serial.h from
>>>> gadget/function to include/linux/usb.
>>>>
>>>> Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
>>> NAK, u_serial uses the gadget API. It's definitely not COMMON.
>>>
>> Okay. It seems that I can't use u_serial anyway. I will implement
>> a new tty glue for my case.
> have you looked at drivers/usb/serial/?
>

Yes, I've checked that. I think usb-serial framework is too complex
for this case. XHCI debug capability is a simple gadget attached to
xHCI host.

Best regards,
Lu Baolu