Date: Mon, 1 Jun 2020 17:36:08 +0200 From: Tomasz CEDRO <tomek@cedro.info> To: Ian Lepore <ian@freebsd.org> Cc: Hans Petter Selasky <hps@selasky.org>, "freebsd-usb@FreeBSD.org" <freebsd-usb@freebsd.org> Subject: Re: arduino usb/com port issue Message-ID: <CAM8r67As2s4Xtczhw-q1_%2B7PYgJszBNhkZQ2trTu2gqvQwWtdQ@mail.gmail.com> In-Reply-To: <351ed893885670e21e2cf66c2afc8b637f1c517a.camel@freebsd.org> References: <59da59d9-f0f0-0b30-f112-1c0af5f5399f@dreamchaser.org> <e17b8319-69c1-de73-678e-b7c9572da927@selasky.org> <CAM8r67Cx9DJ8EHGYmWiZVG_UOBdeyzJWdNKfxz-z_2pzbaAbmA@mail.gmail.com> <351ed893885670e21e2cf66c2afc8b637f1c517a.camel@freebsd.org>
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On Mon, Jun 1, 2020 at 5:28 PM Ian Lepore wrote: > There should be no need to unload ucom to access the low-level usb > device via libusb. I typically have anywhere from 5-8 usb-serial > adapters connected at once, it would be crazy to unload ucom and lose > access to all of them just to use one of them with libusb. > > It is important, however, to avoid accessing /dev/cuaU# or /dev/ttyU# > at the same time that some application is using libusb (or libftdi) to > access that same device. That would cause ucom and the work being done > via libusb to conflict with each other. Exactly the problem here. Either application tries to unload kernel driver just to make sure terminal can connect to a dongle (linux quickfix), or the modem port is already opened with u3g module (more probable scenario). Anyway CMSIS-DAP has its own endpoint that is separate from VCP so it should work without unloading the module. Will verify and send patches to the upstream no worries, thanks for the hints, but that could be another source of problem described by Gary that I found in a similar application :-) -- CeDeROM, SQ7MHZ, http://www.tomek.cedro.infohome | help
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