Re: basler camera on firewire
Brought to you by:
aeb,
bencollins
From: Stefan R. <st...@s5...> - 2011-11-07 21:29:11
|
On Nov 07 Robert Lemmen wrote: > not sure that means anyting, but if i do my modprobe with debug=8 rather > than debug=7 (no idea what any of this exactly means), then plugging in > my camera floods the dmesg with bus reset messages: > > [ 361.873332] firewire_ohci: IRQ 00020000 busReset > [ 361.873340] firewire_ohci: IRQ 00020000 busReset > [ 361.873349] firewire_ohci: IRQ 00020000 busReset > [ 361.873357] firewire_ohci: IRQ 00020000 busReset > [ 361.873366] firewire_ohci: IRQ 00020000 busReset > [ 361.873374] firewire_ohci: IRQ 00020000 busReset > > that can't be right at such a high rate! debug=7 actually means debug=1+2+4, meaning it should log (1) asynchronous packet transmit and receive events, (2) self-ID-complete events with self-ID packet contents, (4) any interrupt events from the set of interrupt types that the driver normally receives. debug=8 means that the driver shall activate reception of bus reset interrupts in addition to the set of the other interrupt event types and log them. (Normally the driver is not interested in getting bus reset IRQs. We only want to know when a bus reset is over and the bus is back in normal operation again --- and for that purpose we receive self-ID-complete IRQs.) Old 1394-1995 hardware used to react with a short burst of bus resets every time when something was plugged in to or out of a bus, and this burst was followed by a self-ID-complete event. With 1394a-2000/ 1394b-2002/ 1394-2008 compliant hardware, you typically get just one, maybe two bus resets and then a self-ID-complete event. By means of the self-ID-complete IRQ, the chip signals to the driver that transmission and reception of self-identification packets by all nodes right after bus reset and automatic enumeration of all nodes. (Unlike old parallel SCSI where node IDs where configured by the user, typically with small jumper switches at the back panel of each device, 1394 node IDs are re-negotiated between all devices at each bus reset.) The self-ID packets carry node IDs, how many ports each node has, parent--child connection relationships of all ports, and more. The fact that you receive boatloads of bus reset events but never a self-ID-complete event with the camera means that the camera is defective (since you checked the card and the cable, and you apparently also ruled out bus power as the problem source). -- Stefan Richter -=====-==-== =-== --=== http://arcgraph.de/sr/ |