NCR(4) BSD Programmer's Manual NCR(4)NAMEncr - NCR/Symbios 53C8xx SCSI driver
SYNOPSIS
ncr* at pci? dev ? function ?
scsibus* at ncr?
option FAILSAFE
option NCR_CDROM_ASYNC
option NCR_IOMAPPED
option NCR_TEKRAM_EEPROM
option NCR_VERBOSE=integer
option SCSI_NCR_DFLT_TAGS=integer
option SCSI_NCR_MAX_SYNC=integer
option SCSI_NCR_MAX_WIDE=integer
option SCSI_NCR_SYMBIOS_COMPAT
option SCSI_NCR_TRUST_BIOS
DESCRIPTION
The ncr driver provides support for the NCR (now Symbios) 53C810, 53C815,
53C820, 53C825, 53C860, 53C875, 53C876, 53C885, 53C895, 53C896, 53C1510,
and 53C1510D SCSI controller chips.
ncr is deprecated and has been replaced by the siop driver.
The following kernel configuration options are available:
option FAILSAFE
Disables tagged command queuing and forces asynchronous transfers for
CD-ROM devices.
option NCR_CDROM_ASYNC
Always use asynchronous transfers with CD-ROM devices. By default, syn-
chronous transfers are used if the CD-ROM supports it.
option NCR_IOMAPPED
Attempt to access the controller chip via I/O port-mapped I/O, falling
back to memory-mapped I/O if the I/O ports couldn't be mapped. By de-
fault, memory-mapped I/O is tried first.
option NCR_TEKRAM_EEPROM
Enables support for reading the configuration EEPROM of the Tekram DC-390
series of SCSI cards. Enable this only if using a Tekram DC-390 card.
option NCR_VERBOSE=integer
Specifies the verbosity of driver messages during a kernel boot. A value
of 1 will provide extra information about the controller's capabilities
and setup. A value of 2 or greater will print information about the
controller's registers.
option SCSI_NCR_DFLT_TAGS=integer
Specifies the maximum number of tags per logical unit. Unless FAILSAFE is
defined, the default value is 4. A value of 0 will disable tagged command
queuing.
option SCSI_NCR_MAX_SYNC=integer
Specifies the maximum synchronous transfer frequency to use, in kHz. A
value of 0 means asynchronous transfers only. The default is 25000
(25MHz), but the actual value used depends on the type of controller chip
and what its maximum transfer rate is. For controllers supporting fast
transfers only, this is 10000 (10MHz). If wide transfers are supported,
the value is 20000 (20MHz).
option SCSI_NCR_MAX_WIDE=integer
Specifies the maximum SCSI bus width, with 0 meaning 8 bits and 1 meaning
16 bits. Defaults to 1 on chips that support wide SCSI, 0 otherwise. Set
this to 0 to disable wide transfers even if both controller and device
support them (e.g. when using a wide controller and wide drive through a
narrow cable).
option SCSI_NCR_SYMBIOS_COMPAT
Enables the use of the GPIO register as a disk activity indicator. Enable
this if the activity LED isn't working, but make sure the card doesn't
use GPIO for something else. Cards known to support this: ASUS SC875, Di-
amond FirePort 40, and Symbios SYM8751S.
option SCSI_NCR_TRUST_BIOS
Specifies that the driver should use the register configuration set by
the firmware instead of configuring the chip itself.
SEE ALSOcd(4), ch(4), intro(4), pci(4), scsi(4), sd(4), siop(4), ss(4), st(4),
uk(4)BUGS
Some Quantum drives (specifically the Atlas series) return "queue full"
responses when a very small number of tags is used which can confuse the
driver. With such drives, you can use
option SCSI_NCR_DFLT_TAGS=0
in your kernel configuration file to disable tagged command queuing.
MirOS BSD #10-current March 24, 2000 1
