On Mon, 9 Aug 2021 17:35:36 -0000 (UTC) Stuart Henderson <[email protected]> wrote:
> On 2021-08-08, Julian Smith <[email protected]> wrote: > > I've been trying to get a yoctopuce (https://www.yoctopuce.com/) USB > > sensor to work on OpenBSD, but have run into problems. > > > > The sensor has Linux code > > (https://github.com/yoctopuce/yoctolib_cpp.git) that uses libusb, but > > on OpenBSD using the libusb1 package, libusb_kernel_driver_active() and > > libusb_detach_kernel_driver() are returning error code -12 > > (LIBUSB_ERROR_NOT_SUPPORTED). > > > > I found some rather old advice saying that these errors can be > > ignored (https://github.com/apple/cups/issues/4088), but then i get an > > error -12 from libusb_submit_transfer(). > > There's no support for detaching a kernel USB driver from userland. > > If the device is attaching to a driver other than ugen, your first is to > prevent that and try again. Devices often attach to uhid(4) and libusb > functionality is very limited there. But that's an easy case to work around, > there's a UQ_BAD_HID quirk (see /usr/src/sys/dev/usb/usb_quirks.c), > you can add an entry using that to prevent the vid/pid of your device > from attaching and build a new kernel, it is then likely to end up on > ugen(4) and then has a better chance to do what you need. Many thanks for this, i've set up a separate machine for experimenting, and built a new kernel as suggested and it all seems to be working now. I'm still getting -12 from libusb_kernel_driver_active() and libusb_detach_kernel_driver() but then things seem to work ok so for example i'm seeing correct-looking CO2 measurements from the device. Here's the diff: cvs server: Diffing . Index: usb_quirks.c =================================================================== RCS file: /cvs/src/sys/dev/usb/usb_quirks.c,v retrieving revision 1.78 diff -u -p -r1.78 usb_quirks.c --- usb_quirks.c 24 Mar 2021 02:49:57 -0000 1.78 +++ usb_quirks.c 11 Aug 2021 22:43:20 -0000 @@ -161,6 +161,9 @@ const struct usbd_quirk_entry { { USB_VENDOR_MICROSOFT, USB_PRODUCT_MICROSOFT_TYPECOVER2, ANY, { UQ_ALWAYS_OPEN }}, +/* Yoctopuce. */ + { 0x24e0, 0x008b, ANY, { UQ_BAD_HID }}, + { 0, 0, 0, { 0 } } }; I tried adding Yoctopuce as vendor 0x24e0 and 0x008b as CO2V2 (it measures CO2 levels etc) to /usr/src/sys/dev/usb/usbdevs but rebuilding the kernel didn't seem to force regeneration of /usr/src/sys/dev/usb/usbdevs.h for some reason, hence the direct use of 0x24e0 and 0x008b in the above patch. Is the device incorrect when it claims to be a Human Interface Device? If so i could maybe contact the manufacture. > > > I notice that 'pkg_info -R libusb1' shows just 9 ports depend on > > libusb1, so i'm wondering whether the libusb1 port is expected to work > > generally on OpenBSD, or whether it be better to try to use the usb(4) > > ioctl API? > > Many more use it via libusb-compat. Support is limited though and there's > some resistance to doing anything to help userland control of USB devices > so if it still doesn't work I'd suggest controlling it from another OS > unless you fancy writing a kernel driver. > Interesting, do you know of somewhere i can read some more about why userland control of USB is not recommended? Now i've managed to get this simple USB device working, i'm vaguely wondering about looking at making a USB terrestrial TV receiver work with Kaffeine on OpenBSD. I was hoping that doing this in user space might be easier than writing a kernel driver, though i guess the data rate might be too high? Thanks, - Jules -- http://op59.net
