RE: Bus Reset
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From: Jeff M. <Jef...@ef...> - 2000-04-12 18:13:48
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Mark, Thanks for the information you provided. The bus reset interrupt would = be generated to the driver when the firewire detects there is a change in condition, right? In this case, I am thinking should it be controlled = by hardware side (Firewire card itself) rather than checking port status register? Thanks, Jeff -----Original Message----- From: Mark Knecht [mailto:mk...@co...] Sent: Wednesday, April 12, 2000 9:37 AM To: Jeff Mak; 'lin...@li...' Subject: RE: Bus Reset The Port Status Registers of a 1394a Phy provide the following = indications: =A0 Connected - Is the cable attached to another 1394 device? Bias - Is that device providing TPBIAS? Disabled - Is this port of our Phy enabled or disabled? =A0 The use of these bits was envisioned as providing the information = necessary to answer the questions you posed Jeff. =A0 I am unclear whether the Linux 1394 driver is taking advantage of these features at this time. It is possible that another thread having to do = with the Sony OHCI implementation may be impacted by the state of these bits also. =A0 Cheers -----Original Message----- From: Jeff Mak [mailto:Jef...@ef...] Sent: Tuesday, April 11, 2000 5:01 PM To: 'lin...@li...' Subject: Bus Reset For OHCI driver, whenever the target node is power off, bus reset would = be generated.=A0=A0 For IEEE1394,=A0 there are some power management i.e. = the node is self-powered and this has been implemented in my target node.=A0=A0 = However, the bus reset signal is still generated causing my linux box cannot = communicate with the target node anymore.=A0=A0=A0 My question is how to = distinguish a target node from "power off" to "connection failed" i.e no bus reset would = generate under "power off" connection ? Thanks,=20 Jeff=20 |