Re: No carrier lost information with gadget RNDIS/ECM

[Felipe Balbi <felipe.balbi@linux.intel.com>]

Hi,

Kai Ruhnau <kai.ruhnau@target-sg.com> writes:
> On my i.MX6 SoloX, I have configured one of the OTG ports for a
> combined RNDIS/ECM gadget. After boot, I have two network interfaces
> (usb0 and usb1) which are managed by systemd-networkd.
>
> With kernel 4.9.153, systemd-networkd reports an immediate carrier
> loss when I pull the USB cable from a Windows or macOS host. With
> 4.19.53 or 5.1.15 that carrier loss is only reported when I re-attach
> the cable, meaning there is a "Lost carrier" for the last used
> interface immediately followed by a "Gained carrier" for the newly
> connected interface.

First of all, thanks for actually testing the most recent stable
kernels. Much appreciated :-)

> I have activated CONFIG_USB_GADGET_DEBUG_FILES, and the contents of
> /proc/driver/rndis-000 don't change when I pull the cable:
>
> Config Nr. 0
> used      : y
> state     : RNDIS_DATA_INITIALIZED
> medium    : 0x00000000
> speed     : 425984000
> cable     : connected
> vendor ID : 0x00000000
> vendor    : (null)
>
> Only when changing the host to a Mac, it's different:
> Config Nr. 0
> used      : y
> state     : RNDIS_UNINITIALIZED
> medium    : 0x00000000
> speed     : 425984000
> cable     : connected
> vendor ID : 0x00000000
> vendor    : (null)
>
> Thanks for any help.

Which peripheral controller is this board using? Is it chipidea? dwc2?
dwc3? High Speed or Super Speed?

-- 
balbi