[U-Boot] [PATCH 1/2] usb: ci_udc: allow multiple buffer allocs per ep

Stephen Warren swarren at wwwdotorg.org
Thu Jun 12 19:42:55 CEST 2014


On 06/12/2014 11:30 AM, Marek Vasut wrote:
> On Thursday, June 12, 2014 at 05:55:40 PM, Stephen Warren wrote:
> [...]
>>>> I'm slightly confused by this log. Do you have 2 boards running U-Boot,
>>>> one running the USB controller in device mode, and this is the log from
>>>> some other board that's talking to that first board?
>>>
>>> I have one board connect to a PC. The log shows two different errors
>>> happening on the board. The first log shows a tftp command on the board
>>> stopping with a timeout after receiving some packets. The second log
>>> shows a tftp command on the same board throwing an error before
>>> receiving any packet.
>>
>> So U-Boot is running on the board, and the logs are from the board, i.e.
>> you're running the "tftp" command in U-Boot on the board?
>>
>> If so, I'm confused how ci_udc comes into play at all; doesn't "tftp"
>> use the USB controller in host mode, whereas ci_udc is only used for
>> device mode?
> 
> U-Boot CDC ethernet support, that's pretty normal mode of operation ;-)

Oh, so that makes U-Boot into a kind of virtual NIC where the packets
don't go anywhere but U-Boot's internal network stack, and that feature
runs in the background with the interactive shell still fully operation
then?

All the USB device mode support I've used is a synchronous/blocking
shell command (dfu, ums) rather than something that runs in the
background, so I figured CDC Ethernet would work the same.

Perhaps I should try and get CDC Ethernet working... Can both
CONFIG_USB_GADGET and CONFIG_USB_ETHER co-exist I wonder? Actually,
U-Boot acting as a USB serial port running at the same time as dfu or
ums would be more useful to me.


More information about the U-Boot mailing list