Date: Thu, 29 Jun 2017 23:26:48 +0200 From: Hans Petter Selasky <hps@selasky.org> To: Matthias Apitz <guru@unixarea.de>, freebsd-usb@freebsd.org Subject: Re: USB devices sometimes not seen at boot time Message-ID: <11fac898-a4bc-8337-2d84-8777d136c7e0@selasky.org> In-Reply-To: <20170629194658.GA2488@c720-r314251> References: <20170629194658.GA2488@c720-r314251>
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On 06/29/17 21:46, Matthias Apitz wrote: > > Hello, > > I have the problem that on my netbook (an Acer C720) sometimes the USB > devices are not seen at boot time while the bus is probed. I filed an > issue as https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=220127 which > did not got any attention so far. > > Meanwhile I was trying to find the rule for the problem and have > investigated the 'dmesg' output for any "good" boot (i.e. the devices > was seen) and compared with "bad" boot (when the device was not seen). > There is a clear dependency of the order the USB bus is probed: > > This is from a good one: > > # egrep 'uhub|ugen' dmesg-20170628-202601-good.txt > ugen0.1: <0x8086 XHCI root HUB> at usbus0 > ugen1.1: <Intel EHCI root HUB> at usbus1 > uhub0: <0x8086 XHCI root HUB, class 9/0, rev 3.00/1.00, addr 1> on usbus0 > uhub1: <Intel EHCI root HUB, class 9/0, rev 2.00/1.00, addr 1> on usbus1 > uhub0: 13 ports with 13 removable, self powered > uhub1: 2 ports with 2 removable, self powered > ugen0.2: <Identiv uTrust 3512 SAM slot Token> at usbus0 > ugen0.3: <SunplusIT Inc HD WebCam> at usbus0 > ugen0.4: <vendor 0x0489 product 0xe056> at usbus0 > > and this is from a bad one: > > # egrep 'uhub|ugen' dmesg-20170628-202351-bad.txt > ugen1.1: <Intel EHCI root HUB> at usbus1 > ugen0.1: <0x8086 XHCI root HUB> at usbus0 > uhub0: <Intel EHCI root HUB, class 9/0, rev 2.00/1.00, addr 1> on usbus1 > uhub1: <0x8086 XHCI root HUB, class 9/0, rev 3.00/1.00, addr 1> on usbus0 > uhub1: 13 ports with 13 removable, self powered > uhub0: 2 ports with 2 removable, self powered > ugen1.2: <vendor 0x8087 product 0x8000> at usbus1 > uhub2 on uhub0 > uhub2: <vendor 0x8087 product 0x8000, class 9/0, rev 2.00/0.04, addr 2> on usbus1 > uhub2: 8 ports with 8 removable, self powered > > The device in question it the "Identiv uTrust 3512 SAM slot Token" and > the rule is: When XHCI is probed as ugen0.1 and later as uhub0, all is > fine; else it fails. > > Any ideas on this? What makes the boot differ in this order? > Hi, USB explores different root HUBs ugen0.1, ugenX.1 and so on in parallell and not serial. Maybe a race or electrical issue is causing the order to fail. You can try compiling a kernel without USB support and loading xhci, ehci, ohci and uhci by a script using kldload. Alternate the loading order. --HPS
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