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Values for ds_flags

The possible flag values in the ds_flags field are listed in Table 5-2. The flag values are designed for the most flexible, capable type of bus, device, and device driver. Not all values are supported, and different host adapters can support different combinations.

Flag Values for ds_flags
Constant NameSupported by Any Driver?Meaning When Set to 1
DSRQ_ASYNCYesReturn at once, do not sleep until the operation is complete.
DSRQ_SENSEYesGet sense data following an error on the requested command.
DSRQ_TARGETNoAct as the SCSI target, not the SCSI initiator.
DSRQ_SELATNYesSelect with ATN.
DSRQ_DISCYesAllow identify disconnect.
DSRQ_SYNXFRYesNegotiate a synchronous transfer if possible. Needed only to switch into synchronous mode. Repeated negotiation is wasteful.
DSRQ_ASYNXFRYesNegotiate an asynchronous transfer. Needed only to return to asynch after a synchronous transfer. Repeated negotiation is wasteful.
DSRQ_SELMSGNoA specific select is coded in the message. This feature is not supported.
DSRQ_IOVYesUse the iov_t from ds_iovbuf, not the single buffer from ds_databuf (see "Data Transfer Options").
DSRQ_READYesThis is a data input command (as opposed to an immediate command or an output).
DSRQ_WRITEYesThis is a data output command (as opposed to an immediate command or an input).
DSRQ_MIXRDWRNoThis command can both read and write.
DSRQ_BUFNoBuffer the input and copy to the supplied buffer, instead of direct input to the buffer.
DSRQ_CALLNoNotify completion (with DSRQ_ASYNC).
DSRQ_ACKHNoHold ACK asserted.
DSRQ_ATNHNoHold ATN asserted.
DSRQ_ABORTNoSend ABORT messages until the bus is clear.Useful only with SCSI commands that have the immediate bit set.
DSRQ_TRACEYesTrace this request (accepted but has no effect).
DSRQ_PRINTYesPrint this request (accepted but has no effect).
DSRQ_CTRL1YesRequest with host control bit 1.
DSRQ_CTRL2YesRequest with host control bit 2.

In order to find out which flags are supported by a particular driver, use the DS_CONF operation (see "Testing the Driver Configuration").


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