From owner-freebsd-usb@freebsd.org Thu Jul 2 10:37:49 2020 Return-Path: Delivered-To: freebsd-usb@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id F2C3E35179E for ; Thu, 2 Jul 2020 10:37:49 +0000 (UTC) (envelope-from jbe-mlist@magnetkern.de) Received: from sapphire.magnetkern.de (sapphire.magnetkern.de [185.228.139.199]) by mx1.freebsd.org (Postfix) with ESMTP id 49yF0r5yjgz4drC for ; Thu, 2 Jul 2020 10:37:48 +0000 (UTC) (envelope-from jbe-mlist@magnetkern.de) Received: from titanium (p5dd45c70.dip0.t-ipconnect.de [93.212.92.112]) by sapphire.magnetkern.de (Postfix) with ESMTPSA id A4F7F1CB1; Thu, 2 Jul 2020 10:37:47 +0000 (UTC) Date: Thu, 2 Jul 2020 12:37:47 +0200 From: Jan Behrens To: Hans Petter Selasky Cc: "freebsd-usb@FreeBSD.org" Subject: Re: USB reset fails when using a LimeSDR Mini on FreeBSD Message-Id: <20200702123747.1bdf36b9d2ebe283f7bb855e@magnetkern.de> In-Reply-To: <8ac365f3-3d33-4730-622e-e66f29dd5938@selasky.org> References: <20200625121052.e9f7e7cbeb68fad264ec80a9@magnetkern.de> <5c0729f9-9e98-52f7-a5cb-6c5dfd2287a3@selasky.org> <20200626172851.872f3a08fa6e632666683230@magnetkern.de> <20200627144419.f14371695d9b62ea99106c4a@magnetkern.de> <20200627173604.7f7b7777140e66dbad812fc7@magnetkern.de> <20200627180420.4b8012fb@ernst.home> <20200702103523.adb0566bcc7b6e354905a8a5@magnetkern.de> <97c8fd11-9200-dff7-4c68-b0b80cc44871@selasky.org> <20200702104743.223e98c325806025704703f2@magnetkern.de> <20200702111538.e7edf0ae8d10ec7ede9acebb@magnetkern.de> <9e14575a-5c8b-28c8-6593-22019a21e7e7@selasky.org> <20200702120655.73d1111e2de81c626be78139@magnetkern.de> <8ac365f3-3d33-4730-622e-e66f29dd5938@selasky.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.32; amd64-portbld-freebsd12.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 49yF0r5yjgz4drC X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org; dkim=none; dmarc=none; spf=pass (mx1.freebsd.org: domain of jbe-mlist@magnetkern.de designates 185.228.139.199 as permitted sender) smtp.mailfrom=jbe-mlist@magnetkern.de X-Spamd-Result: default: False [-2.73 / 15.00]; TO_DN_EQ_ADDR_SOME(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; MV_CASE(0.50)[]; R_SPF_ALLOW(-0.20)[+mx]; MIME_GOOD(-0.10)[text/plain]; DMARC_NA(0.00)[magnetkern.de]; NEURAL_HAM_LONG(-0.99)[-0.995]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_HAM_SHORT(-1.03)[-1.027]; RCPT_COUNT_TWO(0.00)[2]; NEURAL_HAM_MEDIUM(-1.01)[-1.010]; RCVD_NO_TLS_LAST(0.10)[]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:197540, ipnet:185.228.136.0/22, country:DE]; RCVD_COUNT_TWO(0.00)[2]; MID_RHS_MATCH_FROM(0.00)[]; RECEIVED_SPAMHAUS_PBL(0.00)[93.212.92.112:received] X-BeenThere: freebsd-usb@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: FreeBSD support for USB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 02 Jul 2020 10:37:50 -0000 On Thu, 2 Jul 2020 12:18:02 +0200 Hans Petter Selasky wrote: > Hi Jan, > > On 2020-07-02 12:06, Jan Behrens wrote: > > On Thu, 2 Jul 2020 11:23:32 +0200 > > Hans Petter Selasky wrote: > > > >> On 2020-07-02 11:15, Jan Behrens wrote: > >>> On Thu, 2 Jul 2020 10:54:27 +0200 > >>> Hans Petter Selasky wrote: > >>> > >>>> On 2020-07-02 10:47, Jan Behrens wrote: > >>>>> But wouldn't both drivers require access to the entries in /dev ? > >>>> > >>>> Yes, user-space drivers would require access to /dev, yes, but kernel > >>>> drivers not, like mouse, keyboard, storage, network. > >>>> > >>>> [...] > > > I experienced that /dev/usb/2.2.0 and /dev/usb/2.2.1, 2.2.2, 2.2.3, > > etc. get treated differently when I reset the LimeSDR Mini with > > "usbconfig -u 2 -a 2 reset". The devices 2.2.1 and up are supposingly > > re-created (and have their access rights reset), while the device 2.2.0 > > maintains any manually changed access rights. > > > > Let me explain, now you are getting me into dirty details :-) > > This device is used for all of LibUSB interfaces and gives access to all > endpoints: > > /dev/usb/X.Y.0 > > These devices are legacy devices, which allow direct access to the > endpoint via the shell. They are there to support the old user-space > model FreeBSD had. And they are re-created when you reset/reconfigure a > USB device. Actually you can "echo > /dev/usb/X.Y.N" to write directly > to an endpoint from user-space. But don't do that unless it is a modem > endpoint which support AT commands for example. > > /dev/usb/X.Y.[1..15] Are these devices there only for legacy reasons? Or also for granting access to devices via chown/chmod (or devfs.rules)? I see that /dev/ugenX.Y are symlinks to /dev/usb/X.Y.0 I used chown user /dev/usb/2.2.* to get access through libusb (before I set up devfs.rules). > > > Is it correct that 2.2.0 identifies the device as a whole? > > Yes, this is correct. Then I suppose if you have access to /dev/ugenX.Y (i.e. /dev/usb/X.Y. 0), you should be allowed to reset a device. > > >> > >> What do you think? > > > > I'm not sure if this is (from a semantic point of view) the best thing > > to do. I would say you should only be able to reset a device if you > > have been granted access to the device as a whole (including all > > interfaces/subdevices/whatever), as the reset seems to affect all of > > those. > > > > In FreeBSD and LibUSB there is no such concept. Everything is oriented > around interfaces. There is a function to claim an interface, but not > the device itself. (man libusb_claim_interface) That means in order to reset the device itself, I need to claim an interface, e.g. interface 0? But above you said, 2.2.0 identifies the device as a whole (and I noted it is symlinked by /dev/ugen2.2). So I'm a bit confused now. Is /dev/usb/2.2.0 the whole device? Or the interface 0 of the device? Or both... haha > [...] Regards, Jan