Date: Wed, 10 May 2006 02:22:37 -0700 (PDT) From: Tim Clewlow <tim1timau@yahoo.com> To: freebsd-questions@freebsd.org Subject: Unwanted repeated firewire bus reset Message-ID: <20060510092237.85103.qmail@web50307.mail.yahoo.com>
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Hello, I have two firewire devieces, a pcmcia ieee1394 (firewire) card, and a digital video camera with a firewire output plug. I can get digital video from the camera and write it to disk with the fwcontrol utility, and, I can play back the dv (digital video) file with xdvplay. When I play back the dv file, the sound and picture is fine, which tells me that the pcmcia card is working fine, and, the firewire driver is also working to some extent. However, the problem is there are repeated firewire bus resets occurring. Which interrupts the stream of data coming in from the camera. So i get a couple of seconds of playback, then noise, then a few more seconds of playback. There appears to be no apparent reason for the bus reset, because there are only two firewire devices and so there is no real need to constantly re-elect root devices. Also, the data coming in from the camera is (as far as I am aware) isochronous - which means the camera just sends one frame of data every couple of miliseconds, and does not do any error checking to see if the frame arrived intact (similar to upd - send and forget) - this is the normal way of transporting dv data on firewire because it doesnt really matter if a few pixels change color every now and then due to noise. So, given that there is no change in the device topology - ie no firewire devices are being plugged in or out, and, there is no error checking being done with the dv data transport, is there any real need for repeated bus resets, and is there any way I can instruct the firewire driver to not bother with them after the initial device detection reset has been completed. PS - here is a snippet of the ongoing bus resets - the resets occur approximately once every 4-5 seconds - for no apparent reason Kind regards, Tim. ------------------------------- fwohci0: BUS reset fwohci0: node_id=0x8000ffc0, gen=205, non CYCLEMASTER mode firewire0: 2 nodes, maxhop <= 1, cable IRM = 1 firewire0: bus manager 0 (me) fwohci0: BUS reset fwohci0: node_id=0xc000ffc0, gen=206, CYCLEMASTER mode firewire0: 1 nodes, maxhop <= 0, cable IRM = 0 (me) firewire0: bus manager 0 (me) fwohci0: BUS reset fwohci0: node_id=0x8000ffc0, gen=207, non CYCLEMASTER mode firewire0: 2 nodes, maxhop <= 1, cable IRM = 1 firewire0: bus manager 0 (me) fwohci0: BUS reset fwohci0: node_id=0xc000ffc0, gen=208, CYCLEMASTER mode firewire0: 1 nodes, maxhop <= 0, cable IRM = 0 (me) firewire0: bus manager 0 (me) __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
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