[LCA2019 Chat] Headless RPi setup, cdcether not working?

Tue Jan 29 16:02:14 AEDT 2019

On Tue, Jan 29, 2019 at 07:04:24AM +1100, Wes Cilldhaire wrote:
> 
> 
> ----- On 26 Jan, 2019, at 7:17 PM, martin f krafft madduck at madduck.net wrote:
> > On the Pi I just get the message
> 
> > "udc-core: couldn't find an available UDC - added [g_cdc] to list
> > of pending drivers."
> 
> > which the article says means that I didn't enable the dwc2 properly.
> 
> > But hey:
> 
> > # grep dwc /proc/cmdline
> > 8250.nr_uarts=0 bcm2708_fb.fbwidth=656 bcm2708_fb.fbheight=416
> > bcm2708_fb.fbswap=1 smsc95xx.macaddr=B8:27:EB:3B:08:DD
> > vc_mem.mem_base=0x1ec00000 vc_mem.mem_size=0x20000000
> > dwc_otg.lpm_enable=0 console=ttyS0,115200 console=tty1
> > root=PARTUUID=9a617d9a-02 rootfstype=ext4 elevator=deadline
> > fsck.repair=yes rootwait modules-load=dwc2,g_cdc
> > ^^^^^^^^^^
> 
> You need to add the dtoverlay=dwc2 line in config.txt as well so the device actually appears in the device tree for the module to find.
> 
> Yes, I overlooked this step too initially, something about its position in the instructions seems to make one's mind skip over it :)
> (null)

I can't get cdc_ether working

I used the rPi image that was available from the burner near rego.

As indicated here, I did this:
root at raspberrypi:~# grep dwc2 /boot/config.txt 
dtoverlay=dwc2
root at raspberrypi:~# grep dwc2 /boot/*.txt                                                                                             
/boot/cmdline.txt:dwc_otg.lpm_enable=0 console=serial0,115200 console=tty1 root=PARTUUID=b4261201-02 rootfstype=ext4 elevator=deadline
 fsck.repair=yes rootwait splash plymouth.ignore-serial-consoles modules-load=dwc2,g_ether
/boot/config.txt:dtoverlay=dwc2

interface seems to come up:
[    5.655024] dwc2 20980000.usb: 20980000.usb supply vusb_d not found, using dummy regulator
[    5.655159] dwc2 20980000.usb: 20980000.usb supply vusb_a not found, using dummy regulator
[    6.113258] dwc2 20980000.usb: EPs: 8, dedicated fifos, 4080 entries in SPRAM
[    6.154975] dwc2 20980000.usb: DWC OTG Controller
[    6.162747] dwc2 20980000.usb: new USB bus registered, assigned bus number 1
[    6.252180] dwc2 20980000.usb: irq 33, io mem 0x20980000
[    7.044669] g_ether gadget: Ethernet Gadget, version: Memorial Day 2008
[    7.053989] g_ether gadget: g_ether ready
[    7.060353] dwc2 20980000.usb: bound driver g_ether
[    7.189129] dwc2 20980000.usb: new device is high-speed
[    7.236167] i2c /dev entries driver
[    7.565138] dwc2 20980000.usb: new device is high-speed
[    7.693246] dwc2 20980000.usb: new device is high-speed
[    7.766371] dwc2 20980000.usb: new address 10
[    7.787912] g_ether gadget: high-speed config #1: CDC Ethernet (ECM)

I give it an IP:
root at raspberrypi:~# ifconfig usb0
usb0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.2  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::15e4:95ea:e740:aa7d  prefixlen 64  scopeid 0x20<link>
        ether be:e6:a6:5b:35:18  txqueuelen 1000  (Ethernet)

On my computer, I give it an IP too:
root at raspberrypi:~# ifconfig usb0
usb0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.1.2  netmask 255.255.255.0  broadcast 192.168.1.255
        inet6 fe80::15e4:95ea:e740:aa7d  prefixlen 64  scopeid 0x20<link>

dmesg says:
Jan 28 20:38:26 saruman kernel: [728255.209791] usb 1-2: new high-speed USB device number 40 using xhci_hcd
Jan 28 20:38:26 saruman kernel: [728255.358611] usb 1-2: New USB device found, idVendor=0525, idProduct=a4a2, bcdDevice= 4.14
Jan 28 20:38:26 saruman kernel: [728255.358615] usb 1-2: New USB device strings: Mfr=1, Product=2, SerialNumber=0
Jan 28 20:38:26 saruman kernel: [728255.358617] usb 1-2: Product: RNDIS/Ethernet Gadget
Jan 28 20:38:26 saruman kernel: [728255.358619] usb 1-2: Manufacturer: Linux 4.14.79+ with 20980000.usb
Jan 28 20:38:26 saruman kernel: [728255.359846] cdc_subset: probe of 1-2:1.0 failed with error -22
Jan 28 20:38:26 saruman kernel: [728255.361388] cdc_ether 1-2:1.0 usb0: register 'cdc_ether' at usb-0000:00:14.0-2, CDC Ethernet Device, 62:3c:c9:7f:9d:e5

Not sure if cdc_subset probe failed is bad.

If I ping my computer from the rPi, I see its packets on my laptop:
20:58:43.391704 ARP, Request who-has 192.168.1.1 tell 192.168.1.2, length 28
20:58:43.391727 ARP, Reply 192.168.1.1 is-at 62:3c:c9:7f:9d:e5, length 28

But no packet from my laptop never seems to make it back to the rPi.

For those who got it to work, do I have the wrong rPi image or some
other driver problem that causes the rPi not to get packets back in?

Thanks,
Marc
-- 
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                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/                       | PGP 7F55D5F27AAF9D08