[ARM] ARM FAS216: don't modify scsi_cmnd request_bufflen

SCSI doesn't want drivers to modify request_bufflen, so keep a
driver-private copy of this in the scsi_pointer structure instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/drivers/scsi/arm/fas216.c b/drivers/scsi/arm/fas216.c
index 2969cc0..fb5f202 100644
--- a/drivers/scsi/arm/fas216.c
+++ b/drivers/scsi/arm/fas216.c
@@ -633,7 +633,7 @@
 
 	BUG_ON(bytes_transferred < 0);
 
-	info->SCpnt->request_bufflen -= bytes_transferred;
+	SCp->phase -= bytes_transferred;
 
 	while (bytes_transferred != 0) {
 		if (SCp->this_residual > bytes_transferred)
@@ -715,7 +715,7 @@
 		return;
 
 	if (dmatype == fasdma_real_all)
-		total = info->SCpnt->request_bufflen;
+		total = info->scsi.SCp.phase;
 	else
 		total = info->scsi.SCp.this_residual;
 
@@ -753,7 +753,7 @@
 	fas216_log(info, LOG_BUFFER,
 		   "starttransfer: buffer %p length 0x%06x reqlen 0x%06x",
 		   info->scsi.SCp.ptr, info->scsi.SCp.this_residual,
-		   info->SCpnt->request_bufflen);
+		   info->scsi.SCp.phase);
 
 	if (!info->scsi.SCp.ptr) {
 		fas216_log(info, LOG_ERROR, "null buffer passed to "
@@ -784,7 +784,7 @@
 	info->dma.transfer_type = dmatype;
 
 	if (dmatype == fasdma_real_all)
-		fas216_set_stc(info, info->SCpnt->request_bufflen);
+		fas216_set_stc(info, info->scsi.SCp.phase);
 	else
 		fas216_set_stc(info, info->scsi.SCp.this_residual);
 
@@ -2114,6 +2114,7 @@
 	SCpnt->SCp.buffers_residual = 0;
 	SCpnt->SCp.ptr = (char *)SCpnt->sense_buffer;
 	SCpnt->SCp.this_residual = sizeof(SCpnt->sense_buffer);
+	SCpnt->SCp.phase = sizeof(SCpnt->sense_buffer);
 	SCpnt->SCp.Message = 0;
 	SCpnt->SCp.Status = 0;
 	SCpnt->request_bufflen = sizeof(SCpnt->sense_buffer);
diff --git a/drivers/scsi/arm/scsi.h b/drivers/scsi/arm/scsi.h
index 3a39579..21ba571 100644
--- a/drivers/scsi/arm/scsi.h
+++ b/drivers/scsi/arm/scsi.h
@@ -80,6 +80,7 @@
 			 (page_address(SCpnt->SCp.buffer->page) +
 			  SCpnt->SCp.buffer->offset);
 		SCpnt->SCp.this_residual = SCpnt->SCp.buffer->length;
+		SCpnt->SCp.phase = SCpnt->request_bufflen;
 
 #ifdef BELT_AND_BRACES
 		/*
@@ -98,6 +99,7 @@
 	} else {
 		SCpnt->SCp.ptr = (unsigned char *)SCpnt->request_buffer;
 		SCpnt->SCp.this_residual = SCpnt->request_bufflen;
+		SCpnt->SCp.phase = SCpnt->request_bufflen;
 	}
 
 	/*