[PATCH] Add Domain Validation to the SPI transport class

Domain Validation is a fairly essential element to the SCSI Parallel
Interface (although if you look very few drivers actually do it).  The
premise is that the Parallel Bus, being a transmission line, might not
be correctly tuned to the transfers you want do perform.  DV probes the
parameters of the transport until it finds a setting that works (for the
interested, see http://www.t10.org/ftp/t10/drafts/sdv/sdv-r08b.pdf)

The current code employs rather simplistic DV heuristics, although those
can be improved over time.  The change in scsi_scan.c is so that DV may
be done easily from the slave_configure routine, which is the most
natural place to begin.

drivers/scsi/scsi_scan.c

@@ -643,6 +643,10 @@ static int scsi_add_lun(struct scsi_device *sdev, char *inq_result, int *bflags)
 	if (*bflags & BLIST_USE_10_BYTE_MS)
 		sdev->use_10_for_ms = 1;
 
+	/* set the device running here so that slave configure
+	 * may do I/O */
+	scsi_device_set_state(sdev, SDEV_RUNNING);
+
 	if(sdev->host->hostt->slave_configure)
 		sdev->host->hostt->slave_configure(sdev);
 

include/scsi/scsi_transport_spi.h

@@ -35,6 +35,7 @@ struct spi_transport_attrs {
 	unsigned int rd_strm:1;	/* Read streaming enabled */
 	unsigned int rti:1;	/* Retain Training Information */
 	unsigned int pcomp_en:1;/* Precompensation enabled */
+	unsigned int dv_pending:1; /* Internal flag */
 };
 
 /* accessor functions */
@@ -89,5 +90,7 @@ struct spi_function_template {
 
 struct scsi_transport_template *spi_attach_transport(struct spi_function_template *);
 void spi_release_transport(struct scsi_transport_template *);
+void spi_schedule_dv_device(struct scsi_device *);
+void spi_dv_device(struct scsi_device *);
 
 #endif /* SCSI_TRANSPORT_SPI_H */