[PATCH] scsi_transport_spi: fix domain validation failure from incorrect width setting

[James Bottomley <James.Bottomley@SteelEye.com>]

The previous patch was a bit non-standard because it actually adjusted
the user setting max_width.  This would mean that if the user replaced
the cable and then re-ran domain validation, it still wouldn't try wide
transfers, which is wrong.

The attached patch fixes the problem by physically nailing the wide
setting to what it deduces it should be for the whole of Domain
Validation.

James

diff --git a/drivers/scsi/scsi_transport_spi.c b/drivers/scsi/scsi_transport_spi.c
index 6f56f87..bb8a726 100644
--- a/drivers/scsi/scsi_transport_spi.c
+++ b/drivers/scsi/scsi_transport_spi.c
@@ -787,10 +787,12 @@ spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
 	struct scsi_target *starget = sdev->sdev_target;
 	struct Scsi_Host *shost = sdev->host;
 	int len = sdev->inquiry_len;
+	int min_period = spi_min_period(starget);
+	int max_width = spi_max_width(starget);
 	/* first set us up for narrow async */
 	DV_SET(offset, 0);
 	DV_SET(width, 0);
-	
+
 	if (spi_dv_device_compare_inquiry(sdev, buffer, buffer, DV_LOOPS)
 	    != SPI_COMPARE_SUCCESS) {
 		starget_printk(KERN_ERR, starget, "Domain Validation Initial Inquiry Failed\n");
@@ -798,9 +800,13 @@ spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
 		return;
 	}
 
+	if (!scsi_device_wide(sdev)) {
+		spi_max_width(starget) = 0;
+		max_width = 0;
+	}
+	
 	/* test width */
-	if (i->f->set_width && spi_max_width(starget) &&
-	    scsi_device_wide(sdev)) {
+	if (i->f->set_width && max_width) {
 		i->f->set_width(starget, 1);
 
 		if (spi_dv_device_compare_inquiry(sdev, buffer,
@@ -809,6 +815,11 @@ spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
 		    != SPI_COMPARE_SUCCESS) {
 			starget_printk(KERN_ERR, starget, "Wide Transfers Fail\n");
 			i->f->set_width(starget, 0);
+			/* Make sure we don't force wide back on by asking
+			 * for a transfer period that requires it */
+			max_width = 0;
+			if (min_period < 10)
+				min_period = 10;
 		}
 	}
 
@@ -828,7 +839,8 @@ spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
 
 	/* now set up to the maximum */
 	DV_SET(offset, spi_max_offset(starget));
-	DV_SET(period, spi_min_period(starget));
+	DV_SET(period, min_period);
+
 	/* try QAS requests; this should be harmless to set if the
 	 * target supports it */
 	if (scsi_device_qas(sdev)) {
@@ -837,14 +849,14 @@ spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
 		DV_SET(qas, 0);
 	}
 
-	if (scsi_device_ius(sdev) && spi_min_period(starget) < 9) {
+	if (scsi_device_ius(sdev) && min_period < 9) {
 		/* This u320 (or u640). Set IU transfers */
 		DV_SET(iu, 1);
 		/* Then set the optional parameters */
 		DV_SET(rd_strm, 1);
 		DV_SET(wr_flow, 1);
 		DV_SET(rti, 1);
-		if (spi_min_period(starget) == 8)
+		if (min_period == 8)
 			DV_SET(pcomp_en, 1);
 	} else {
 		DV_SET(iu, 0);
@@ -862,6 +874,10 @@ spi_dv_device_internal(struct scsi_device *sdev, u8 *buffer)
 	} else {
 		DV_SET(dt, 1);
 	}
+	/* set width last because it will pull all the other
+	 * parameters down to required values */
+	DV_SET(width, max_width);
+
 	/* Do the read only INQUIRY tests */
 	spi_dv_retrain(sdev, buffer, buffer + sdev->inquiry_len,
 		       spi_dv_device_compare_inquiry);