Hi, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> writes: >> I have been trying to get a UVC gadget running through configfs and >> wired in to dummy_hcd. >> >> I have largely been following the instructions from the Tizen wiki. >> https://wiki.tizen.org/USB/Linux_USB_Layers/Configfs_Composite_Gadget/Usage_eq._to_g_webcam.ko >> >> However I am getting a hard lockup, I believe when device is started. >> The system does not respond to any commands, including SYSRQ. >> >> A bash script I have been executing to set it all up is attached, as is the log. >> >> I am running in a VM against v4.14-rc2. I have the same issues with >> v4.13 and with the recent setup_timer() patch set. The v4.10 kernel >> had other issues which have since been corrected. >> >> The last log lines are: >> + echo dummy_udc.0 >> [ 92.086000] udc dummy_udc.0: registering UDC driver [g1] >> [ 92.086620] configfs-gadget gadget: adding 'uvc'/ffff9f6ab8a965f0 >> to config 'c'/ffff9f6aba715520 >> [ 92.087544] configfs-gadget gadget: uvc_function_bind >> [ 92.089110] dummy_hcd dummy_hcd.0: port status 0x00010101 has changes >> ~~~ end of transmission ~~~ >> >> >> Is there anything obvious that I have done wrong or an area I should >> start looking? >> >> I have very little kernel experience but am happy to poke at things >> with GDB like a small child until something happens. However with the >> size of the code base I would appreciate some pointers on where to >> start poking. > > Does uvc use isochronous transfers? I assume it would, since it's a > video protocol. yes, it does :-) > dummy-hcd does not support isochronous. I don't know what would happen really? Then why is it registering iso endpoints to the gadget layer? static const struct { const char *name; const struct usb_ep_caps caps; } ep_info[] = { #define EP_INFO(_name, _caps) \ { \ .name = _name, \ .caps = _caps, \ } /* everyone has ep0 */ EP_INFO(ep0name, USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL, USB_EP_CAPS_DIR_ALL)), /* act like a pxa250: fifteen fixed function endpoints */ EP_INFO("ep1in-bulk", USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)), EP_INFO("ep2out-bulk", USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep3in-iso", USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)), EP_INFO("ep4out-iso", USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep5in-int", USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)), EP_INFO("ep6in-bulk", USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)), EP_INFO("ep7out-bulk", USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep8in-iso", USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)), EP_INFO("ep9out-iso", USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep10in-int", USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)), EP_INFO("ep11in-bulk", USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)), EP_INFO("ep12out-bulk", USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep13in-iso", USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_IN)), EP_INFO("ep14out-iso", USB_EP_CAPS(USB_EP_CAPS_TYPE_ISO, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep15in-int", USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_IN)), /* or like sa1100: two fixed function endpoints */ EP_INFO("ep1out-bulk", USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep2in-bulk", USB_EP_CAPS(USB_EP_CAPS_TYPE_BULK, USB_EP_CAPS_DIR_IN)), /* and now some generic EPs so we have enough in multi config */ EP_INFO("ep3out", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep4in", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)), EP_INFO("ep5out", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep6out", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep7in", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)), EP_INFO("ep8out", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep9in", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)), EP_INFO("ep10out", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep11out", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep12in", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)), EP_INFO("ep13out", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), EP_INFO("ep14in", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_IN)), EP_INFO("ep15out", USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_OUT)), #undef EP_INFO }; > if you tried it, but one way or another it would not work the way you > want. if that's really the case, then maybe we should remove all the iso endpoints from dummy. Right? -- balbi
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