Date: Wed, 16 Jan 2013 16:00:25 -0800 From: Oleksandr Tymoshenko <gonzo@bluezbox.com> To: Jakob Alvermark <jakob@alvermark.net> Cc: freebsd-arm@freebsd.org Subject: Re: Isochronous USB transfers on RPI? Message-ID: <50F73F19.20401@bluezbox.com> In-Reply-To: <78AB4FEC-6E16-4FCA-B172-3C7B37FEA4DF@alvermark.net> References: <6BD0E5E4-3921-4F9B-9381-3813933670AE@alvermark.net> <201301161319.17236.hselasky@c2i.net> <78AB4FEC-6E16-4FCA-B172-3C7B37FEA4DF@alvermark.net>
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On 1/16/2013 6:29 AM, Jakob Alvermark wrote: > Hi, > > I see that there is code, I'm not just very good at reading and writing it. :-) > > usbdump is quiet on the Pi > On my laptop I can see ISOC packets when using the same webcam and software so something is missing. I'm not familiar with webcam configuration on freebsd but do you have all the components setup on RPi? Kernel driver and/or userland bits? > > /Jakob > > On 16 jan 2013, at 13:19, Hans Petter Selasky wrote: > >> On Wednesday 16 January 2013 10:25:38 Jakob Alvermark wrote: >>> Hi, >>> >>> Maybe this should go to the usb list, but it is probably relevant here as >>> well. I have been playing with the Pi for a while now and having great fun >>> with FreeBSD. Great work gonzo and others! >>> However, I'd like to use a webcam with it. I learned that USB webcams use >>> isochronous transfers and the DWC OTG driver doesn't fully implement it. >>> (If I read the commit logs correctly) >>> What is missing and how can I help? >>> >> Hi, >> >> The DWC OTG driver has not fully implemented isochronous. Using isochronous >> transfers will have a high CPU load impact, because 1000 IRQ's (FS) or 8000 >> IRQ's (HS) second will be needed to feed the FIFOs. However, if this is >> acceptable, code can be found in: >> >> sys/dev/usb/controller/dwc_otg.c >> >> --HPS >> > _______________________________________________ > freebsd-arm@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-arm > To unsubscribe, send any mail to "freebsd-arm-unsubscribe@freebsd.org" >
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