** Description changed: + [Impact] + On the RPI4B board, the usb-c power port could also work as a USB + OTG mode, but we set the dwc2 driver to the host mode + unconditionally, now set it to dual_role mode, then it could work + in host/otg/peripheal mode. + + [Fix] + Set USB_DWC2_DUAL_ROLE=y, USB_DWC2_HOST=n + + + [Test Case] + set the dtoverlay=dwc2,dr_mode=[otg|peripheral] in the config.txt, + and isnmod the g_ether or g_cdc, on the host machine, we could see + RPI4B work as a usb device. + + Because physical port limitation, could test dr_mode=host. + + [Regression Risk] + Low, our eoan kernel choose dwc_otg driver for this port by default, + very very few users will choose dwc2 driver, and the dwc2 driver is + not enabled by default in our kernel. + + And bug reporter and I already tested that the peripheral mode works + after this change. + + 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)
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1861070 Title: Raspberry Pi 4B: USB OTG is not working To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-raspi2/+bug/1861070/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
