Date: Fri, 03 Jan 2014 14:13:20 +0100 From: Hans Petter Selasky <hps@bitfrost.no> To: "Lundberg, Johannes" <johannes@brilliantservice.co.jp>, "freebsd-usb@freebsd.org" <freebsd-usb@freebsd.org> Subject: Re: usb_interrupt_read speed different on USB 2 vs 3 port. Message-ID: <52C6B770.401@bitfrost.no> In-Reply-To: <CAASDrV=Onk2VbnSp-1s=XxJ0b89-M8--NWOeFPXjSgMLC8sVEA@mail.gmail.com> References: <CAASDrV=Onk2VbnSp-1s=XxJ0b89-M8--NWOeFPXjSgMLC8sVEA@mail.gmail.com>
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On 01/03/14 13:59, Lundberg, Johannes wrote: > Hi > > I had a bug driving me crazy and I finally discovered something weird that > was the reason. > > I have a pair of AR glasses from Vuzix which have a > gyro/accelerometer/compass which I read from USB using usb_interrupt_read > (reading 42 bytes of data). > > On my laptop I have two USB 2 and one USB 3 port. > >>From the USB 2 port things behave normally and reading takes a millisecond > or so. > >>From the USB 3 port things get weird and the call to usb_interrupt_read > takes over 20 milliseconds. I have been running this device on the same > laptop for some time and haven't noticed this behavior before. > > Can it be something that has been introduced recently or perhaps only my > system is behaving weird?... > > # uname -a > FreeBSD PC 10.0-BETA1 FreeBSD 10.0-BETA1 #0: Sun Dec 8 16:15:23 JST > 2013 root@PC:/usr/obj/usr/src/sys/GENERIC i386 > > Best regards > -- > Johannes Lundberg > Hi, Can you show output from "usbconfig -d X.Y dump_device_desc dump_curr_config_desc" In both cases? --HPS
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