Hi Hui, just in case I tried again, but no it won't work if I put "dtoverlay=dwc2" w/o dr_mode. I remember dwc2 should be new code and should be used, hence why I use that instead of dwc_otg.
Anyway, if we use "dtoverlay=dwc2" only, I guess the actual "dr_mode" value may not be init properly in run time memory space, and thus it didn't work. Say using no "dr_mode", on my Pi 4B I can see g_cdc driver loaded correctly, but then on the host side, my L470, it actually won't work. Something like this would appear: ----- pi4 ----- [ 5.317371] udc-core: couldn't find an available UDC - added [g_cdc] to list of pending drivers ... [ 7.497909] g_cdc gadget: CDC Composite Gadget, version: King Kamehameha Day 2008 [ 7.497913] g_cdc gadget: g_cdc ready [ 7.497921] dwc2 fe980000.usb: bound driver g_cdc ----- L470 ----- [44740.491468] usb 1-3.1: new high-speed USB device number 18 using xhci_hcd [44741.837984] usb 1-3.1: device descriptor read/64, error -71 [44757.718734] usb 1-3.1: device descriptor read/64, error -110 [44757.902877] usb 1-3.1: new high-speed USB device number 19 using xhci_hcd [44763.350132] usb 1-3.1: device descriptor read/64, error -110 [44779.223840] usb 1-3.1: device descriptor read/64, error -110 [44779.329078] usb 1-3-port1: attempt power cycle [44779.942228] usb 1-3.1: new high-speed USB device number 20 using xhci_hcd [44785.366277] usb 1-3.1: device descriptor read/64, error -110 [44801.236885] usb 1-3.1: device descriptor read/64, error -110 [44801.423944] usb 1-3.1: new high-speed USB device number 21 using xhci_hcd [44806.870008] usb 1-3.1: device descriptor read/64, error -110 [44822.743518] usb 1-3.1: device descriptor read/64, error -110 [44822.849333] usb 1-3-port1: unable to enumerate USB device but if I use "dtoverlay=dwc2,dr_mode=peripheral" then no problem. I didn't test the Ethernet part yet as I don't have the network part properly set up, so I tried g_cdc instead, bind console to ttyGS0 with systemd and tried login from L470 to Pi via minicom, which was successful. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux-raspi2 in Ubuntu. https://bugs.launchpad.net/bugs/1861070 Title: Raspberry Pi 4B: USB OTG is not working Status in linux-raspi2 package in Ubuntu: New Bug description: I am using Raspberry Pi 4B (4GB) and want to make use of the OTG functionality (g_ether). I cross checked with Raspbian to make sure it is not a hardware issue. Extract from dmesg of Ubuntu 19.10.1 with latest updates applied as of Jan 26th, 2020 via "apt-get update" and "apt-get full-upgrade": ... [ 1.514262] dwc_otg: version 3.00a 10-AUG-2012 (platform bus) [ 1.517365] dwc_otg: FIQ enabled [ 1.517376] dwc_otg: NAK holdoff enabled [ 1.517386] dwc_otg: FIQ split-transaction FSM enabled [ 1.517399] Module dwc_common_port init ... [ 6.358332] dwc2 fe980000.usb: fe980000.usb supply vusb_d not found, using dummy regulator [ 6.358388] dwc2 fe980000.usb: fe980000.usb supply vusb_a not found, using dummy regulator [ 6.358545] dwc2 fe980000.usb: Configuration mismatch. dr_mode forced to host [ 6.409098] dwc2 fe980000.usb: DWC OTG Controller [ 6.409399] dwc2 fe980000.usb: new USB bus registered, assigned bus number 3 [ 6.409432] dwc2 fe980000.usb: irq 23, io mem 0xfe980000 ... [ 111.796714] udc-core: couldn't find an available UDC - added [g_ether] to list of pending drivers I think it is that "Configuration mismatch. dr_mode forced to host" log entry telling me that the port is acting as HOST mode instead of OTG mode. I have try putting these in usercfg.txt "dtoverlay=dwc2" "dtoverlay=dwc2,dr_mode=otg" "dtoverlay=dwc2,dr_mode=peripheral" and it will give the same result, no OTG functionality. On the same hardware running Raspbian Buster, it initialise successfully. Corresponding dmesg: ... [ 0.567531] dwc_otg: version 3.00a 10-AUG-2012 (platform bus) [ 0.570391] dwc_otg: FIQ enabled [ 0.570400] dwc_otg: NAK holdoff enabled [ 0.570409] dwc_otg: FIQ split-transaction FSM enabled [ 0.570421] Module dwc_common_port init ... [ 2.507634] dwc2 fe980000.usb: fe980000.usb supply vusb_d not found, using dummy regulator [ 2.511011] dwc2 fe980000.usb: Linked as a consumer to regulator.0 [ 2.514450] dwc2 fe980000.usb: fe980000.usb supply vusb_a not found, using dummy regulator [ 2.731860] dwc2 fe980000.usb: dwc2_check_params: Invalid parameter lpm=1 [ 2.735511] dwc2 fe980000.usb: dwc2_check_params: Invalid parameter lpm_clock_gating=1 [ 2.735522] dwc2 fe980000.usb: dwc2_check_params: Invalid parameter besl=1 [ 2.735533] dwc2 fe980000.usb: dwc2_check_params: Invalid parameter hird_threshold_en=1 [ 2.735582] dwc2 fe980000.usb: EPs: 8, dedicated fifos, 4080 entries in SPRAM [ 2.752511] dwc2 fe980000.usb: DWC OTG Controller [ 2.752554] dwc2 fe980000.usb: new USB bus registered, assigned bus number 3 [ 2.752601] dwc2 fe980000.usb: irq 36, io mem 0xfe980000 ... [ 2.848843] g_ether gadget: Ethernet Gadget, version: Memorial Day 2008 [ 2.851601] g_ether gadget: g_ether ready [ 2.854580] dwc2 fe980000.usb: bound driver g_ether [ 2.998525] dwc2 fe980000.usb: new device is high-speed [ 3.075025] dwc2 fe980000.usb: new device is high-speed [ 3.139338] dwc2 fe980000.usb: new address 10 [ 3.154010] g_ether gadget: high-speed config #1: CDC Ethernet (ECM) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-raspi2/+bug/1861070/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
