NAME

dmv − DEC DMV-11 point-to-point communications device

SYNTAX

device dmv0 at uba0 csr 0167600 flags 0x???? vector dmvrint dmvxint

DESCRIPTION

The dmv interface provides access to a point-to-point communications device which runs at speeds from 2.4 Kb/s to 56 Kb/s. DMV-11’s communicate using the DEC DDCMP link layer protocol.

Several protocols can be multiplexed over a dmv link simultaneously.  Conversely, a dmv can be set up such that only one protocol family can use that device. If the latter approach is taken, an SIOCSTATE ioctl must be issued by the protocol family requesting device ownership.  The family’s address must appear in the “if_family” structure member, and “if_nomuxhdr ” must be set.  Before requesting ownership, the device’s current ownership should be read and saved.  This will allow device ownership to be returned to a previous owner.

The first byte of the flags word can be set up to indicate what mode the device should use.  The supported modes are 0 for full duplex, 1 for maintenance mode, and 2 for half duplex as a primary station.  In addition, the driver will assume dmc compatibility mode unless bit 2 of the first byte is set.  The number of outstanding transmit buffers can be increased from a default of 7 to a maximum of 24 buffers by specifying a hexadecimal value in the second byte of the flags word. For example, if flags is set to 0x1800, then 24 transmit buffers will be allocated on a device set up to run full duplex in dmc compatibility mode.

DIAGNOSTICS

dmvprobe: can’t start device.  The dmv could not be started at boot time.

dmvprobe: device failed diagnostics, octal failure code = %o.  The dmv failed diagnostics at boot time.

dmvinit: can’t place dmv%d into internal loopback.  Unable to place the dmv into internal loopback requested by user.

dmv%d: done unalloc rbuf.  The device returned a receive or transmit buffer that was not allocated to it. 

dmv%d: unknown address type %d.  An input packet was received that contained a type of address uknown to the driver. 

dmv%d bad packet address 0x%x.  The device returned a buffer with an unexpected buffer address. 

dmv%d: unsolicited information response: ctl = %x, data = %x.  The device interrupted the driver with an information response when none was requested. 

dmvd%d: bad control %o.  A bad parameter was passed to the dmvload routine. 

dmv%d: modem disconnect.  The modem disconnected or there was a loss of carrier while a packet was being received. 

dmv%d: buffer too small.  The remote node sent a packet that was too large to fit in the allocated receive buffer. 

dmv%d: receive threshold reported.  The dmv reported a receive threshold error.

dmv%d: transmit threshold reached.  The dmv reported a transmit threshold error.

dmv%d: select threshold reached.  The dmv reported a select threshold error.

dmv%d: babbling tributary reported.  The dmv reported a babbling tributary error.

dmv%d: streaming tributary reported.  The dmv reported a streaming tributary error.

dmv%d: MOP mode entered while DDCMP was running. 
dmv%d: MOP mode entered while device was halted. 
The dmv has entered MOP mode.

dmv%d: non existent memory reported.  The dmv accessed non-existent memory.

dmv%d: device queue overflow reported.  The dmv reported a queue overflow.

dmv%d: invalid counter pointer.  The dmv is reporting the contents of a counter when no request was made to do so.

dmv%d: can’t handle af%d.  The dmv was handed a transmit message which has addresses formatted in an unsuitable address family.

dmv%d: internal loopback enable requested.  The device is being put in internal loopback at a user’s request. 

dmv%d: internal loopback disable requested.  The device is being taken out of internal loopback at a user’s request. 

dmvwatch: dmv%d hung, bse10=%b, bsell = %b, bse12=%b.  The device has not responded after a long period of time.